#### JOHN J. KNAPP, TRUSTEE, ET AL. v. THE UNITED STATES.

[No. 28292.

Decided October 30, 1911.]

*On the Proofs.*

Tbe subject of tbis suit is a patented device for sponging out guns so as to prevent flarebacks and explosions. Tbe three claimants are officers of tbe Government, and tbe claimants Knapp and Dunn are employed and assigned to duty in tbe development and manufacture of tbe same device in tbe Government shops. Before tbe granting of their respective patents tbe three claimants enter into an agreement whereby their two patents shall become the common property of the three, and Knapp shall be trustee to hold the patents for the benefit of all. After tbe filing of their applications and before tbe issuance of the patents, the claimants give notice to the Navy Department, “ *That while the parties interested, in these applications recognize the Government’s right to property in the specific apparatus embodying the sañd. inventions, constructed at the Government’s cost and with the inventor’s consent and allowance, we notify the department that further application of the said iwoentions, or either of them, is not authorized save upon the expectation bythe parties of a reasonable compensation.”*Tbe Secretary of the Navy replies that the claimants Knapp and Dunn were officers in the Bureau of Ordnance and were assigned to the duty of developing tbe device under the direction of the bureau and in tbe line of their duty; and that “ *the department will proceed with the manufacture and use of the device,'leaving the question as to whether the patentees should receive compensation, to determination by the courts’’*To this the claimants answer that they are “ *content."*It appears that the claimant Sawyer was not assigned to the duty of developing the. invention; but it also appears that tbe device covered by his patent was anticipated by that of Knapp and Dunn.

I. Where an officer of tbe Government is properly assigned to tbe task of devising, preparing, or making an instrument or implement for the public service, the Government bearing the expense, the officer receiving bis salary for his services, a presumption of implied contract does not arise.

II. Tbe omission of the Patent Office to decide upon the question of priority between two inventors does not preclude tbe court from inquiring. In this case Sawyer can not recover because bis invention was anticipated by that of Knapp and Dunn, and Knapp and Dunn can not recover because their device *602was tested and developed at the expense of the Government and under the direction of the Bureau of Ordnance.

III. If an inventor should allow his invention to be developed, tested, and used in the shop of his employer without notice that he • claims a property therein, no contract can be implied, and he will be precluded by his silence from afterwards maintaining an action for damage.

IV. In this case the development and use of the device in the Government shops without an intimation from Knapp and Dunn that they claimed or intended to claim any property therein has estopped them from seeking compensation; and the correspondence between them and the Secretary of the Navy, by which it was proposed that the department should continue to manufacture, leaving the right to compensation to be determined by the courts, did not create a contract giving them a right to compensation. The cases reviewed.

V.Implied contracts do not arise from the denials and contentions of parties. The correspondence of the Secretary of the Navy did not imply an intent to contract, for it set up reasons why no contract could be implied.

VI.An invention dates from the time of the filing of an application for a patent, if there be no sufficient proof to establish an earlier date. Priority can not be proved by the inventor’s mere allegation where there has been no disclosure to others or embodiment of the invention in perceptible form.

*The Reporters'*statement of the case.

The following are the facts of the case as found by the court:

I. July 8, 1904, the claimant, trustee, became by an instrument in writing (Finding VII) the assignee of Frederick Lewis Sawyer to an invention described" in an application for letters patent of the United States, filed by the said Sawyer May 26, 1904, as serial No. 209951, and issued as Patent No. 782701, February 14, 1905, to Frederick L. Sawyer, assignor to John J. Knapp, trustee.

July 6, 1904, the claimant, trustee, became by an instrument in writing (Finding VII) the assignee of John J. Knapp and George W. Dunn to an invention described in a joint application for letters patent of the United States, filed by the said Knapp and Dunn June 10, 1904, as serial No. 212009, and issued as Patent No. 783050, February 21, 1905, to John J. Knapp and George W. Dunn, assignor to John J. *603Knapp, trustee, copies of which letters patent are made part of paragraph 1 of the petition as Exhibits 3 and 4.

II. For some time prior to the filing dates of the applications for the patents in suit the subject of obtaining an efficient gas and smoke expelling device for use on the turret guns of the Navy had been under consideration and experiment by officers in the service, and various devices had been used.

In the fall of 1903 a gas and smoke expelling device was designed by Ordnance Engineer Williams under the direction of the Bureau of Ordnance, and this design was adopted and installed upon the U. S. S. *Illinois,*and used in the target practice of the ship in the spring of 1904 with satisfactory results.

The plan of boring holes radially into the blanks of the screw box for the admission into the bore of the gun of air under pressure, in a manner substantially similar to that subsequently employed in devices applied to the turret guns of the Navy, and which is now in question in this suit, was discussed by officers on the U. S. S. *Illinois*between September 21, 1903, and the latter part of December, 1903, and Lieut, de Steiguer then examined the screw box of the turret guns on the *Illinois*as to the feasibility of boring such holes, and determined it was feasible so far as the work was concerned, but in the hurry to get the ship ready for sea and for lack of facilities permission to bore such holes was not asked.

III. The importance of the subject was later brought to the attention of the Navy Department by the following communication, addressed to the Secretary of the Navy on the date stated, viz:

“ 165 Madison StReet,

“ *Brooklyn, N. Y., March 25th, 1904.*

“ The Honorable Seceetaky oe the. Navy,

“ *Washington, D. 0.*

“ Sir : The accompanying blue prints are plans of a new device which we have invented for the purpose of extracting gases from the bore of a gun passing out through the muzzle, thereby preventing them from escaping into the turret, while the breechblock is being opened, which they at present do.

“ Our invention is a very simple and not an expensive attachment or ejector, through which water is forced under *604pressure at an angle with, the axis of the gun; as this covers the entire periphery of the muzzle, it naturally keeps out any wind from the bore; while the breechblock is being opened to receive a new charge, a current of air enters (caused by the siphoning process the ejector does) and escapes through the muzzle, carrying the gases and smoke with it.

“A test could be made very reasonably by connecting a line of pipe from the ejector at the muzzle to any pump in the vicinity of the turret; hose would answer the purpose for a test. The device could be stowed away when not in use.

“ Very respectfully,

“ ALEXANDER BOTJCHER.

“ Thomas J. McCloskey.”

'Which letter was referred the next day to the Bureau of Ordnance, and thereafter the chief of said bureau referred the same by the following indorsement to the Washington Navy Yard:

“ Navy Department,. *March 26,1901¡,.,*

“ Respectfully referred to the Bureau of Ordnance for reply to writer.

*“*By direction of the Secretary of the Navy:

“ B. F. Peters, *Chief*Cleric.”

“ [ 1st endorsement.}

“ No. 3549.

“ Bureau of Ordnance, *April 11,190*

“ Respectfully referred to the Washington Navy Yard.

“ 1. The bureau requests that this method of drawing the smoke from the chamber and bore of the gun be investigated and an experimental device, fitted for the use of both air and water ejector, be made and tried to determine if such means of freeing the gun of smoke can be made effective for service use.

*“*2. It is requested that this subject receive early consideration, as the question of flames and smoke in turrets during action or target practice is considered to be very important.

, “ G. A. Converse,

“ *Chief of Bureau of*Ordnance.”

Upon receipt of communications of this kind from the bureau in which orders to manufacture are included it was customary at the Washington Navy Yard to first make copies of a sufficient number for the drafting room, inspection officer, foremen of the shop in which the work is to be done, and *605the shipping officer, in case a shipment is made, and such other persons as may be directly interested. The copies of orders or suggestions for experimental work are almost without exception distributed before the order cards for the commencement of the work are issued. This course was followed in this instance.

The work described in this order was done by direction of Foreman Lynch, under whom Master Mechanic George W. Dunn, a civilian employee in the navy yard, was then serving.

At and for some time prior and subsequent to April 11, 1904, Lieut. Commander Knapp, one of claimant’s assignors, was on duty at the Washington Navy Yard as an inspector of ordnance, guns, mounts, etc., having an office in the room with several other inspectors where copies of all orders from the Bureau of Ordnance were sent upon their receipt at the yard. During a like period George W. Dunn, another of claimant’s assignors, was master mechanic at the Washington Navy Yard. Knapp’s duties were to inspect and direct the assembling of guns and their mounts, and Dunn’s duties were in charge of the work of erecting guns and their mounts. Said navy yard and the naval officers there on duty were under the direction of the Bureau of Ordnance.

IV. On April 13, 1904, a fatal accident occurred on the U. S. S. Missouri, occasioned by an explosion in one of the gun turrets. When the news of the accident was received at the Bureau of Ordnance on the afternoon of April 13, 1904, the subject of a means for preventing such accidents was discussed by the chief of the bureau, Admiral Converse, with Lieut. Commander Chase, assistant to the bureau. The chief of the bureau on the same day, when informed by Chase of his scheme or the general idea of his plan, authorized the use of the *Iowa's*8-inch gun for the purpose of installing and testing the plan at the Washington Navy Yard, and directed Chase to give the necessary instructions to that-effect.

On the same afternoon, April 13, Chase, in consultation with Lieut. Latimer, worked out the design of a means for expelling gases from the bore of guns by the use of a cleaning medium, such as steam, air and water, or air, said clean*606ing medium to be admitted into the blanks of the screw box through radial holes drilled therein in such a way as to enable it to enter the bore of the gun as soon as the gas check was unseated. Chase disclosed to Latimer by description and sketches the nature of the design, and requested Latimer to bring it to the attention of Lieut. Commander Knapp, whe was on duty at the Washington Navy Yard, when he next visited the yard.

Latimer followed the direction of Chase to inform Knapp of this plan, which he did on the morning of April 14, 1904, in a conversation had by him with Knapp, and he indicated to Knapp how the radial holes could be drilled through tire breech of the gun and into the blank spaces of the screw box, and suggested to Knapp that this plan determined upon by Chase and himself be tried by application to a dummy breech mechanism which was then in the gun shop, and Latimer indicated on said dummy breech how the holes for admitting the cleaning medium could be drilled. In response to the question of Knapp whether the guns would stand such drilling and whether the Bureau of Ordnance would permit it, Lati-mer informed him that Chase considered they would. Dunn was present during part of the conversations between Knapp and Latimer and neither Knapp nor Dunn on that occasion made any claim to Latimer that they, or either of them, had designed a gas-expelling device of like or similar nature to the one designed and suggested by Chase and Latimer, nor did Knapp or Dunn then suggest any such plan.

On April 21, 1904, seven days after the visit of Latimer to the Washington Navy Yard and the disclosure by him on the morning of April 14 to Knapp and Dunn of the plan Chase had suggested, Knapp in his official capacity submitted to the superintendent the following memorandum:

“ Uotted States Navy YaRd,

“ 'Washington, *D. 0., April 81, 1901)..*

“ I forward a sketch and brief description of device for extinguishing burning matter in a bore of a gun, and also prevent blowbacks, which has been developed by Master Mechanic Dunn, under my direction.

“ The jet of air and water has been tried and proved successful. It may be that the air jet alone will be all that is required. If this proves to be the case, the use of water may *607be omitted without causing any essential change in this device.

“Authority is requested to fit a gun with this device. As sizes of openings may require change by experiment, it is suggested that 8-inch gun No. 62, returned from the *Iowa,*be utilized in further developing this device, or that No. 61, also returned from the *Iowa*and now at Indian Head, be utilized if it can be returned. If this latter gun is used, it could, upon completion of tests here, be sent to Indian Head for proof test.

“ Very respectfully, '

“ John J. Knapp,

*“Lieutenant Commander, U. 8. Navy”*

The superintendent addressed the Bureau of Ordnance as follows:

“ U. S. Navy Yakd,

“ *Washington, D. G., Apr. 21,1901.*

“ Sik : 1. Forwarded herewith is a sketch and brief description of device for extinguishing burning matter in, the bore of the gun, and also preventing blowbacks, which has been developed by Master Mechanic Geo. W. Dunn, under the direction of Lieut. Commander John J. Knapp, IJ. S. N.

“ 2. The jet of air and water has been tried and has proved successful. It may be that the air jet alone will be all that is required.. If this prove to be the case, the use of water may be omitted without causing any essential change in the device.

“ 3. Authority is requested to fit a gun with this device. As sizes of openings, etc., may require change by experiment, it is suggested that 8" gun No. 62, returned from the U. S. S-*Iowa,*be utilized in further developing this device, or that No. 61, also returned from the *Iowa*and now at Indian Head, be utilized if it can be returned. If this latter gun is used, it could, upon completion of tests here, be sent to Indian Head for proof tests.

“ Respectfully,

“ E. C. Pendleton,

“ *Captain, U. 8. N., 8upt. Narval Gun Factory. ‘*

“ Bureau of Oednanoe,

“ *Navy Dept., Washn., D. ON*

To which the bureau responded as follows:

“ DEPARTMENT OF THE NAVY,

“ Bureau of Ordnance,

“ *Washington, D. C., April 23, 1901$.*

*“*Sir : Referring to the letter of the superintendent of the Naval Gun Factory, No. 3256, of the 21st instant, enclosing a *608sketch and, description of a device for extinguishing burning matter in the bore of the gun:

“ 1. The bureau approves the fitting of this arrangement on 8-inch gun No. 61, now at the naval proving ground.

“ 2. The initial experimental tests of firing this gun will be had on next Wednesday, and it is expected that the gun can be returned to the yard under your command on the following day, Thursday. When it is received, the bureau requests that the smoke-expelling device be fitted to it, and that its length be reduced by 5 calibers from the muzzle end before returning it to the naval proving ground for the continuation of the experimental firing.

“ Respectfully,

“ Y. O. Chase,

*“Acting Chief of Bureau of Ordnance.*

*“*To the COMMANDANT WASHINGTON NaVT YaRD.”

The chief of the bureau, as set forth in Finding IV, had previously directed the installation of the device upon an 8-inch gun from the Iowa, and the bureau continued to direct the experimental tests of the gas-ejecting device according to the design which it considered had been suggested -by it through Chase and Latimer. The device was subsequently tested, as shown by the following report:

“ No. 1548. “ Naval PRoving Ground,

*“Indian*Head, Md., *June 1904~*

“ Sir: Referring to the bureau’s No. 4645 of April 23 and No. 6203 of June 4, 1904, I have to state that on Saturday, June 18, in the presence of the special experimental board, the smoke-expelling device mentioned in the above endorsements was tried in the 8-inch cut-off *Iowa*gun.

“ 2. The two shots were fired with reduced charges in order to test the mechanism. In these two shots also double ignition charges were used — namely, T grains of S. X. F. black prismatic ignition powder in each end of each of the two sections of powder — the powder being S. P. 207, 43 pounds and 52 pounds, respectively.

*“*3. After these two rounds the test in connection with the *Iowa’s*powder was commenced and continued, the smoke-expelling device being used in each case. Two of the members of the board left after about four shots had been fired, but the experiments were continued in my presence as a member and in charge of the proving ground until evening, when seven shots had been fired.

“ 4. The compressor used was the small 500-pound combined motor and compressor recently forwarded here by the *609bureau, the tank having been sent down from the Washington Navy Yard. The compressor is a high-speed one and charges comparatively rapidly, but the air became very hot, and it is the intention to install some kind of cooling apparatus, and if these compressors are to be used on board ship such cooling apparatus will be absolutely necessary. The capacity of this compressor can be gaged from the, fact that it took ten minutes to pump up the tank and the piping, which are about 18.9 cubic feet, from 0 to 97 pounds at the gage. The automatic governor worked very well, starting and stopping the machine as the pressure fell and rose. Each expelling and firing reduced the pressure about 5 pounds when the compressor was not running and about 1 pound when running.

“ 5. In the first three or four shots air alone was used with the apparatus, and in some of the subsequent shots the combination of air and water, and then air alone again. In every instance the apparatus worked most satisfactorily, the bore being cleared almost instantaneously in *&*puff and before the block was opened.

“ 6. The regulation of the water with the crude arrangement of two plain globe valves in our installation was not as fine as it might have been, and this feature was not so satisfactory. Another feature developed, and that is a dead space immediately in front of the mushroom, but it is understood from Lieutenant Commander Knapp that this had been discovered at the gun factory and a remedy was being incorporated in the improved design.

“ 7. I consider it a very valuable and successful device for this important work in connection with gun firing.

(Signed) “A. C. DieffeNbach,

“ *Lieutenant, United States Navy,*

“ *Inspector of Ordnance in Charge.*

“ Chief of Bureau of Ordnance,

“ *Navy Department, Washington, D.*C.”

While the work of installing and testing the device on the *Iowa*was being done Chase and Latimer visited the yard and directed modifications and changes therein in the presence of Knapp and Dunn, neither of whom then claimed to have originated the design, nor were they consulted about the changes so made.

The first knowledge obtained by either the chief of the bureau, Chase, or Latimer of any intention by Knapp and Dunn to apply for a patent for such a device was when their *610patent attorney, Mr. Church, visited the bureau on or about July 16, *1904,*and asked it to request the Patent Office to expedite the examination of- the application theretofore filed for patent. The bureau declined to take the action requested because it considered that its subordinates had first designed the device in question, and that the same had been developed by the claimants’ assignors under its direction acting in the line of their duty, and Mr. Church was so informed.

Following this visit to the bureau by Mr. Church, attorney for Knapp and Dunn, Chase and Latimer went to the navy yard and Latimer there insisted that he had first disclosed to Knapp the plan of constructing the gas ejector in question and had at that time, April 14,1904, informed him and Dunn that the plan had been previously designed and outlined by Chase and himself in the bureau.

V. Lieut. Commander Bristol, an officer of extended experience in ordnance matters, and who was judge advocate of the court of inquiry into the causes of the *Missouri*accident, April 27, 1904, wrote the following letter to Chase, inclosing a sketch of his design:

“ U. S. S. Beooklyn, *Wednesday.*

“ My Dear Chase :

“ I have just finished up the *‘*record,’ and the court is through unless H. S. B. wants some revising done. I hope he will not. I have had more than enough, and have missed the firing trials that I came here for. It is hard luck, but I have gained a lot of other knowledge that is good for us. By the way, I had thought of a scheme before the *Mo.’s*accident for an air jet. Since then several have suggested the same thing, so I send it on.

“ What do you think of it ? The orifices to be in the blanks in the screw box. Hope to be with you soon. Will find out to-morrow. My best to all.

“ Yrs., “ Bristol.”

Shortly after writing the foregoing letter, Bristol, who was then on the Brooklyn, met Lieut. Sawyer, who was visiting the wardroom officers of the *Brooklyn,*and Bristol explained and illustrated to Sawyer the design which he had conceived and which he had disclosed in his letter to Chase.

- Sawyer stated to Bristol that he had a scheme to prevent such accidents which was different from his, but in what particular he did not disclose either by word or drawing.

*611At the time of this meeting between Bristol and Sawyer the latter was attached to the *Nevada,*then off Pensacola, Fla. On March 17, 1904, when the turret guns were being tested, he had experienced in his turret a blast of flaming gases from the breech of one of the guns as soon as it was opened, which singed his hair and eyebrows and also singed one or more of the men. After the completion of the target practice off Pensacola, about May 1,.1904, the *Nevada*proceeded to Annapolis, Md., arriving there on or about May 6, 1904. On the following day Sawyer came to Washington and consulted with a patent attorney, Ernest Wilkinson, Esq., relative to filing an application for patent upon “ Improvements in means for sponging out guns.”

VI. On or before May 13, 1904, the installation at the Washington Navy Yard of the gas and smoke expelling device upon the 8-inch gun from the Iowa, which had been proceeding under the direction of the Bureau of Ordnance, was practically completed, and said device was in successful operation at that time. The installation of this device upon the 8-inch gun of the *Iowa*was done during business hours in one of the shops at the yard, where it was open to the observation of visitors to the gun factory. Mr. Wilkinson was a frequent visitor to the gun factory and was in a position to have knowledge of this work of installation.

For a period of at least 12 days prior to the filing of Sawyer’s application for patent this device installed at the navy yard had been reduced to practice and was a practically completed and operative device. The application of Sawyer was filed May 26, 1904, and this is the earliest date of his invention ; nor was the same reduced by him or by anyone for him to practice.

The application of Knapp and Dunn was filed on June 10, 1904, for the invention claimed to have been made by them on April 14, 1904, but it appears, as before stated, that the invention of substantially the same character of device was made by Chase and Latimer on the afternoon of April 13, 1904, and was disclosed to Knapp and Dunn by Latimer on the morning of April 14, 1904.

Chase and Latimer, as well as Knapp and Dunn, were at the time of their alleged inventions, respectively, on duty *612under the direction of the Bureau of Ordnance. The gas-expelling device in question in this suit was developed in the shops of the Naval Gun Factory, at Washington, at Government expense and under the supervision of Government officials. Its practical application to use as well as its development by said officials was under the direction of the Bureau of Ordnance, both in the Washington Navy Yard and at Indian Head.

The device so conceived by Chase and Latimer, subsequently modified by them and developed and tested under the direction of the Bureau of Ordnance aforesaid, is substantially the device embodied in the patents in suit.

VII. On June 2 or 3,1904, Knapp, who was then suspicious of the claim of Sawyer to priority of invention of a similar device to the one installed on the 8-inch gun from the *Iowa*at the Washington Navy Yard, which was completed and the device operative as early as May 13, 1904, had a conference with Sawyer at Annapolis, Md. As a result of this and other conferences between the parties the following contract was entered into:

“AGREEMENT.

“ Whereas Frederick L. Sawyer, lieutenant, United States Navy, attached to the U. S. S. Nevada, Annapolis, Maryland, has made application for letters patent of the United States for improvements in sponging out guns, which application was filed on the 26th day of May, 1904, and was serially numbered 209951;

“And whereas the said Frederick L. Sawyer has also executed applications for the same invention to be filed in Great Britain, France, and Germany;

“And whereas John J. Knapp, lieutenant commander, United States Navy, stationed at the Washington Navy Yard, Washington, D. C., and George W. Dunn, master mechanic at the same navy yard, have filed a joint application for letters patent of the United States on the 10th day of June, 1904, serially numbered 212009, and entitled £ Improvements in ordnance ’;

“And whereas the said Sawyer, Knapp, and Dunn may conclude to file other applications for United States and foreign patents on the inventions aforesaid and for improvements thereon;

“And whereas it is the desire of the said Sawyer, Knapp, and Dunn that all such applications already filed or executed, *613or to be hereafter filed by any of the three parties to this agreement for the inventions aforesaid, or for any improvements thereon that either the said Sawyer, Knapp, or Dunn, or any of them, may make, shall become the joint property of the parties aforesaid:

“ Now, therefore, it is agreed by and between the said Sawyer, Knapp, and Dunn, as follows:

“ I. That the inventions and applications aforesaid and the patents accruing therefrom shall be the joint property of the said Sawyer, Knapp, and Dunn, and any profits arising from the practice of the inventions aforesaid, sale of patent rights, payment of royalties, or in any manner whatsoever received, shall be the joint property of the said Sawyer, Knapp, and Dunn, and shall be divided equally between them;

“ II. That the parties aforesaid shall share equally in any and all legitimate expenses incurred in the exploiting of the invention or inventions aforesaid and securing the patents, and in any other way that may be requisite to maintain the property rights aforesaid;

“ III. That the said Sawyer and the said Knapp and Dunn shall transfer to the said Knapp, as trustee, for the use and benefit of said three parties, on demand of said Knapp, the said inventions, applications, and patents to be granted on said applications, in order that the said Knapp, trustee, may exploit said inventions, both in the United States and foreign countries, either by the sale of the same or of interests in the same, or by the granting of licenses upon royalty thereunder, or otherwise; all necessary and legitimate expenses in connection with such sale or exploitation to be divided equally between the parties aforesaid.

“ IV. It is further agreed by and between the said Sawyer, Knapp, and Dunn, that should any of the three parties to this agreement fail to honor the demand of said Knapp, trustee, for his share of the expenses incurred in connection with the invention aforesaid for a period of sixty days after the receipt of said demand by the party aforesaid, all of the property rights of the delinquent, in the inventions and the patents aforesaid, shall become forfeited; and the amount of said delinquency shall be divided equally between the parties not delinquent, and they shall then become the joint owners of all the said property rights;

“ V. Should any two of the three parties to this agreement conclude to withdraw from the same, then all property rights shall become vested in the third party, provided he assume the amount of the delinquency of the other two parties;

“ VI. But nothing in ibis agreement shall be held as a waiver by any party hereunto of his liability of his one-third *614of the expenses, in case all three of the parties conclude to terminate the agreement;

*“*VII. It is further agreed by and between the parties aforesaid, that each shall contribute, within fifteen days from the date of this contract, the sum of two hundred dollars ($200), the amount to be deposited to the credit of John J. Knapp, trustee, out of which sum the actual and legitimate expenses shall be paid as they accrue;

“ VIII. It is provided further that in taking out any patents, either i-n the United States or in foreign countries, other than those already applied for, or other than those for which applications have already been executed, any party may suggest to the others that he is desirous of taking out such patent or patents; and if all three assent, then the expenses shall be shared equally; and the profits, if any, shall be shared equally; and if one or both of the other parties decline to assume his or their share of expenses, then this declination shall be considered a waiver of all rights in said patent or in said inventions in the country or countries in which said additional patents are to be secured;

“ IX. It is further agreed by and between the parties aforesaid, that the question of priority of invention between F. L. Sawyer and J. J. Knapp and G. W. Dunn shall be submitted to Messrs. Ernest Wilkinson and Melville Church, and if they fail to agree, then the matter shall be referred to an arbitrator selected by them, whose decision shall be final.

“ X. And furthermore, the said John J. Knapp hereby accepts the trusteeship hereby established, and agrees that any money received in connection with the business aforesaid shall be deposited in a separate bank from his own personal account, and to the credit of John J. Knapp, trustee ; and he further agrees to keep an account of all receipts and expenses, which account shall be open to the inspection of either of the other parties to this agreement upon reasonable notice.

“ Feedbrick Lewis Sawyer.

“ Signed at Old Point Comfort, Va., this the 27th day of June, 1904.

“ In presence of—

' *“*Mark St. Clair Ellis.

“ George G. Mitchell.

“ Signed at Washington, D. C-, this the 28th day of June, 1904.

“ John J. Knapp, *Lieut. GomdrU. S. N.*

“ Geo. W. Dunn, *M. M.*

“ In presence of—

“Wm. Falconer.

“M. A. Lynch.”

*615The question of priority of invention between the parties to said contract, referred to in paragraph 9 thereof, does not appear to have been determined as therein provided, nor was the question raised or settled in the Patent Office. Prior to the issuance of the patents in suit certain of the claims in the Knapp and Dunn application were canceled and transferred or put into the Sawyer application by amendment thereof, thus attempting to avoid the probable interference between the two applications in the Patent Office, and giving to the Sawyer patent the broader claims of the Knapp and Dunn application.

VIII. The copies of the blue prints numbered 22910, 23163, 21849, 22886, 22274, 22766, 22492, 22455, 23213, 22928-9, 22729, 22971, 23281, 23289, 22457, 21904, 21876, relating to the general arrangement of the gas ejectors for guns for the Navy, submitted in this case by the Navy Department, August 11, 1906, represent all the material features of the device used in the Navy and the subject of suit.

The device as shown by the drawings submitted by the Navy Department, above cited, and as in actual use, is substantially covered by the following claims in the Sawyer patent:

“ 1. The combination with an air pipe at the breech of the gun, with a plurality of air ducts leading from said pipe into the screw-box exterior to the breech plug, a valve normally controlling the admission of air to said pipe, means for supplying compressed air to said valve, and means carried by the gun for opening said valve, substantially as described.

“ 2. The combination with an air pipe at the breech of the gun, with a plurality of air ducts leading from said pipe into the screw-box exterior to the breech plug, a valve normally controlling the admission of air to said pipe, means for supplying compressed air to said valve, and automatic means operated by the rearward motion of the breechblock for opening said valve, substantially as described.

“ 7. The combination with an air pipe at the breech of the gun, and an air duct leading from said pipe into the screw-box exterior to the breech plug, of a valve normally controlling the admission of air to said pipe, means for supplying compressed air to said valve, and means carried by the gun for opening said valve, substantially as described.

“ 8. The combination with an air pipe at the breech of the gun, and an air duct leading from said pipe into the screw-*616box exterior to the breech plug, of a valve normally controlling the admission of air to said pipe, means for supplying compressed air to said valve, and automatic means operated by the rearward motion of the breechblock for opening said valve, substantially as described.

“ 34. In breech-loading ordnance, the combination with the gun and removable breechblock therefor, of the supply for cleaning medium, nozzle for directing the cleaning medium into the breech of the gun, a valve for said supply opened by the opening movement of the breechblock and a yielding connection for permitting the breechblock to be closed without moving the valve; substantially as described.

“ 35. In breech-loading ordnance, the combination with the gun, the removable breechblock having a gas check at its forward end and a supply for cleaning medium under pressure, of a nozzle opening into the breech chamber in rear of the gas check for the admission of cleaning medium, and a valve controlling the admission of said medium, substantially as described.

“ 36. In breech-loading ordnance, the combination with the gun, the removable breech block having a gas check at its forward end and a supply for cleaning medium under pressure, of a plurality of nozzles opening into the breech chamber in rear of the gas check and_ in the space around the breech-block, and a valve controlling the admission of the cleaning medium, substantially as described.

“ 37. In breech-loading ordnance, a supply for cleaning medium, and a valve controlling such supply, and means whereby said valve is automatically opened by the opening of the breech, substantially as described.”

And in the Knapp and Dunn patent claims:

“ 1. In a cleaner for the purpose specified, the combination with the gun and removable breechblock therefor, of the supply for cleaning medium, nozzle for directing the cleaning medium into the breech of the gun and a valve controlling said supply having an operating handle extending into the path of the breechblock to be moved thereby to open the valve and contacting with a side portion of the breechblock to hold the valve open during the opening movement of the breechblock; substantially as described.

“ 2. In a cleaner for the purpose specified, the combination with the gun and removable breechblock therefor, of the supply for cleaning medium, nozzle for directing the cleaning medium into the breech of the gun and a valve controlling said supply having an operating handle extending into the path of the breechblock to be moved thereby to open the *617valve, and having a yielding end portion to permit the breechblock to return to its seat when the valve is closed.

“ 6. In breech-loading ordnance, the combination with the gun mount, the gun movably mounted thereon and a nozzle for the admission of cleaning medium to the breech of the gun, of an extensible duct for the supply of cleaning medium and a relief valve in said duct, substantially as described.

“ 7. In breech-loading ordnance, the combination with the gun mount, the gun movably mounted thereon, and a nozzle for the admission of cleaning medium to the breech of the gun, of a duct embodying telescoping sections one connected with the mount and another with a gun, and a relief valve in said duct, substantially as described.”

IX. On August 15,1904, the claimant herein, in his capacity as trustee for the parties named in the applications for patents, and before letters patent had issued, for the first time gave notice of any intention to assert a claim against the defendants and presented, through his attorneys, a claim for compensation for the alleged use of the devices described in said applications, as appears from the following letter:

“ HERBERT & MlCOU,

“ 1419 G Street Northwest,

“ Washington, *D. G., August 15,1904.*

“ Sir : Representing John J. Knapp, lieutenant 'commander, U. S. N., in his capacity of trustee, as hereinafter set forth, we would respectfully represent to you as follows:

“ 1. That on May 26, 1904, Frederick L. Sawyer, lieuten-antj U. S. N., made application for letters patent of the United States for certain new and useful improvements in sponging out guns, the same being known and designated as Application Serial No. 209951.

“ 2. That on June 10,1904, John J. Knapp, lieutenant commander, U. S. N., and George W. Dunn, master mechanic, made a joint application for letters patent of the United States for certain new and useful improvements in ordnance, the same being known and designated as Application Serial No. 212009.

“ 3. That the title to both said applications and to the inventions therein shown and described, and to any patent or patents that may be granted for said inventions, or either of them, is duly vested in the above-mentioned John J. Knapp, as trustee for the benefit of the said Sawyer, Knapp, and Dunn.

“ 4. That the inventions applied for by these officers in the Government service do not relate to a matter as to which *618either of them was especially directed to experiment as a part of his official duty with the view to suggesting improvements, but .come within that class of inventions which a person in the military service of the United States has a right to patent, and which it has been held the United States does not have the right to use without making proper compensation therefor.

“ 5. That the inventions embraced in the aforesaid applications have already been by the United States Government applied to an 8-inch gun at the U. S. Navy Yard, Washington, D. C., and have been tested with satisfactory results at the proving grounds at Indian Head, Maryland.

“ 6. That the trustee above mentioned, as such trustee and on his own behalf, and the other parties whom he represents, are desirous that the Government should have the full benefit of the aforementioned invention, upon rendering proper compensation therefor to the owners thereof.

“7. That on July 14, 1904, Patent Attorneys Church & Church, who are representing the parties interested in securing these patents, on the ground that the Government, as well as the applicants, were interested in the fate of these applications, preferred a request to the honorable Secretary of the Navy that he would ask the Patent Office to expedite the examination of the applications, and on July 22, 1904, the department replied that it did not deem it advisable to request such action in this case. That the passing upon the applications for these patents by the Patent Office will therefore have to take the usual course, and it niay be some time before the same are acted upon.

“ 8. That the parties interested are advised that other practical applications of the said inventions, other than the application referred to as already having been to an 8-inch gun at the U. S. Navy Yard, Washington, D. C., are in contemplation by the Government in the near future, possibly before the Patent Office may have acted upon the pending applications.

“ 9. Therefore, on account of the facts above stated, and that no misunderstanding may arise about the matter, we herewith respectfully advise the department that while the parties interested in these applications recognize the Government’s right to property in the specific apparatus embodying the said inventions applied to the aforesaid 8-inch gun, such apparatus having been constructed at the Government’s cost and with the inventors’ consent and allowance, we beg to notify the department that further application of the said inventions, or either of them, is not authorized by the applicants for patents save upon the expectation by the parties applying for the same of a reasonable compensation for *619license upon the part of the Government for any use of said inventions further than as the same has already been applied to the aforementioned 8-inch gun.

“ 10. Furthermore, we respectfully represent that the parties interested in these applications stand ready, for a reasonable compensation, to convey to the Government a full legal title to their said inventions, applications, and patents, or to grant a license, exclusive or otherwise, to the Government for a reasonable royalty for the use of their inventions, and to take up with the Government, when it may see fit so' to do, the question of agreeing upon the amount of compensation and the matter of paying the same for the use of these inventions.

“ Respectfully, “ Heebert & Micóu,

“ *Counsel for Trustee.*

“ The honorable Secretary oe the Navy.”

The attitude of the Navy Department relative to the foregoing proposition for compensation appears from the following indorsements and letter:

“ [Second indorsement.]

“ Navy Department,

“ Oeeice oe the Judge Advocate General,

*“August 18,190*A

“ Respectfully referred to the Bureau of Ordnance, requesting report and recommendation.

“ By direction of the Secretary:

“ S. W. B. Diehl,

“ *Judge Advocate General.'1’’*

*“*[Third indorsement.]

“August 24, 1904.

“ Subject: Messrs. Herbert &'Micou, under date Aug. 15, 1904, re use by Government of certain improvements in ordnance invented by Sawyer, Knapp, and Dunn.

“ 1. Respectfully returned to the Navy Department; attention invited to the bureau’s letter of even date upon the subject of this communication.

“ N. E. Mason,

*“Chief of Bureau of OrdnanceT*

“ Department oe the Navy,

“ Bureau oe Ordnance,

*“Washington, D. C., August*&£, *190k*

“ Sir : Referring to lettér of Messrs. Herbert & Micou, relating to the alleged invention of Lieutenant Commander *620John J. Knapp, U. S. N., and Master Mechanic George W. Dunn.

“ The bureau begs to submit the following observations:

“ 1. In the bureau’s opinion there is ground for serious doubt as to the validity of the claim of the above-mentioned applicants for letters patent for ‘ Certain new and useful improvements in sponging out guns.’ The exact principle of the device referred to was for some time under consideration and discussion in the bureau, and so far as the bureau is aware the specific idea of introducing jets of air, steam, or water into the powder chamber .of a gun through holes bored into the screw box was first communicated to Lieutenant Commander Knapp about April 14, 1904, by an officer from the bureau, and the development and construction of an experimental apparatus was then by its representative authorized. The bureau had knowledge of the action taken by its representative immediately after that officer’s return to the bureau, and at no time suspected that the device under construction at the Naval Gun Factory was in any way regarded as other than a piece of work being performed by the bureau’s authority and at the bureau’s instigation until July last. At that time the bureau received a visit from a patent attorney, who asked that, in the interests of Lieutenant Commander J. J. Knapp and Master Mechanic George W. Dunn, his clients, the bureau request the Patent Office to expedite action upon an application for letters patent for this invention. Under the circumstances the bureau declined to prefer this request. The bureau has no knowledge of the specific claims of the. applicants for a patent, but it has no reason to doubt, from its present knowledge, that the idea of the only novel and valuable feature of the device originated in the bureau and that the manufacture of an experimental apparatus for trial was authorized, as is often done, by verbal order of one of its officers.

“ 2. It would seem, therefore, that there is a reasonable ground to doubt the claim of originality on the part of the applicants for a patent. Should, however, this aspect of the matter be left out of consideration for the moment, the bureau is of opinion that neither Lieutenant Commander Knapp nor Master Mechanic George W. Dunn is entitled to deprive the bureau of the use of the device, even though either of them originated the idea, since its conception and the development and manufacture of the experimental apparatus in the Government shops was in direct line of their duty.

“ 3. The question of securing adequate means of freeing the bores of guns from dangerous gases had assumed a position of serious importance several months before the accident to the Missouri, and in October, 1903, a compressed-air jet *621attachment had been ordered fitted to one of the 13-inch guns of the Illinois, to blow into the breech upon withdrawing the breech plug. Another device for drawing the gases from the bore by an attachment on the muzzle of the gun was presented to the bureau’s consideration and referred to the Washington Navy Yard on April 11, 1904, with directions from the bureau to investigate the proposed plan and construct an experimental apparatus for trial, the bureau concluding its endorsement as follows:

“ £ It is requested that this subject (of freeing the gun of smoke) receive early consideration, as the question of flames and smoke in the turrets during action or target practice is considered to be very important-.’

“ 4. Lieutenant Commander Knapp has charge of the inspection and has supervision of the construction of all turret guns and mounts, with all fittings and appliances connected with them. Master Mechanic Dunn has charge of the erecting shop for turret gun mounts and supervises the assembling of the mounts and the correction of all mechanical difficulties brought to light when this material is assembled.

“ 5. The Government is, therefore, in the bureau’s opinion, entitled to the benefit of the skill and ingenuity of both these subordinates in devising and constructing apparatus to overcome any difficulty that may be brought to their attention. Were the Government not entitled to call upon the best efforts of its employees (especially in the case of a commissioned officer) to perfect its manufactured material when these employees are engaged in the direct line of their duty, it would be greatly handicapped, and certainly improvements and developments of all features of ordnance construction would be seriously retarded, and any workman or draftsman who might, in the course of his work, conceive of an improved method for accomplishing any desired end, could either withhold his idea or patent it to secure royalty upon his invention.

“6. The bureau encloses statement by Lieutenant J. L. Latimer, U. S. N., the officer referred to in the foregoing as having visited the Washington Navy Yard as its representative.

“ Respectfully, “ N. E. Mason,

“ *Chief of Bureau of Ordnance.*

“ The Secretary of the Navy.”

“ [Fourth indorsement.]

“ Navy Department, *August §1,1901.*

“ Returned to the Bureau of Ordnance.

“ In view of the facts set forth in the papers accompanying the indorsement (3d) herewith of the Bureau of Ordnance, *622the suggestion is made, for consideration by the officers named below, that, with a view to the protection of such interests as the Government may have in the premises, Lieutenant Commander Chase or Lieutenant Latimer, or both said officers conjointly, as may be deemed proper, make application for a patent for the within-mentioned improvement in ordnance, conceived by them and developed under the bureau’s direction at the Washington Navy Yard, in order that, in connection with the pending applications within referred to, the question of title may be raised and considered in the Patent Office, attention being here called to the provisions of the act or March 3,1893 (22 Stat., 625), with regard to the granting of patents to officers of the Government for inventions to be used in the public service.

“ The return of these papers is desired.

“ Moeton, *Secretary.'”*

“ [Fifth indorsement.]

“ Sept. 23, 1901.

“Subject: Herbert & Micou, use by Government of improvements in ordnance said to have been invented by Sawyer, Knapp, and Dunn.

“ Respectfully returned, to the department.

“ 1. After duly considering the recommendation contained in the 4th indorsement hereon, the bureau thinks that a preferable course for the department to pursue in relation to the subject matter of this communication would be for the bureau to continue the manufacture of the apparatus for which an application for letters patent is now pending without regard to the claimants; and should a patent be issued to the claimants, and they feel themselves entitled to royalty for any use which the Government may have made of their invention, they may then have recourse to the Court of Claims for redress. ■

“2. From the bureau’s point of view, as it does not for itself desire to secure a patent for this invention, and as the same, to the best of its knowledge, has been inspired and developed under its direction by its own subordinates in the direct line of their duty, this appears to be the more dignified and correct course to pursue, thereby relieving the bureau of the semblance of an attitude of opposition to the issuing of a patent for this invention and leaving to the law officers of the Government the determination of the facts and application of the law in this case.

“ N. E. Mason,

*“Chief of Bureau of Ordnance.”*

*623“ Navy Department,

*“WasMngton, October 13,1901.*

“ Gentlemen : Receipt is acknowledged of your letter of the 15th of August last, relative to the question of use by the Government and payment of royalty therefor of a device for sponging out guns, claimed to have been invented by Lieutenant Commander J. J. Knapp and Lieutenant F. L. Sawyer, U. S. N., and George W. Dunn, master mechanic at the navy yard, Washington, and on which letters patent have been applied for by them.

“ The Bureau of Ordnance, to which the matter was submitted for report and recommendation, states in an indorsement dated the 23d ultimo that the invention in question, ‘ to the best of its knowledge, has been inspired and developed under its direction by its own subordinates in the line of their duty.’

“Lieutenant Commander Knapp and Mr. Dunn were among the subordinates referred to in the statement quoted above, and the department will authorize the bureau to proceed, as recommended by it, with the manufacture and use of the device mentioned, leaving the question as to whether said patentees, if letters be issued to them, should receive compensation, and if so in what amount, on account of such manufacture and use to determination by the courts upon the facts of the case.

“Very respectfully,

(Sgd.) “ Paul Morton,

*“Secretary.*

“ Messrs. Herbert & Micou,

*“Attorneys at Law, 1119 G Street N~W.,*

*“'Washington, D. G.n*

“ [Sixth indorsement.]

“Navy Department,

“ Oefice op the Judge Advocate General,

*‘‘''October 11,1901.*

“ Respectfully referred to the Bureau of Ordnance for its information and attention invited to the department’s letter of the 13th instant (press copy herewith) to Messrs. Herbert & Micou with regard to the within matter.

“ The return of these papers is requested.

“ By direction of the Secretary:

“E. P. Hanna,

*“Acting Judge Advocate*General.”

*624To the foregoing letter of the Secretary claimant, through his attorneys, made the following reply:

“ Fleming Building, 1419 G StReet NW.,

“ *Washington, D. 0., October %$, 190¡¡,.*

“Sir: Representing John J. Knapp, trustee, as set forth in our letter to you of August 15, 1904, we have the honor to acknowledge receipt of the department’s letter of the 13th instant, and beg to state that our client is content that the Navy Department should proceed with the manufacture and use of the device concerning which this correspondence relates, leaving it, when letters patent issue to the applicants, to the courts to determine, upon the facts of the case, the compensation and amount that should be received on account of the manufacture and use hereby assented to.

“ Respectively,

“ HERBERT & MlCOU.

“ The honorable the Secretary of the Navy.”

X. A flareback is a burst of flame to the rear upon opening the breech of guns in the firing of which inflammable gases are generated at enormous pressure and under great heat. It is attributable to the oxygen of the air outside uniting with the oxygen of the highly inflammable gases from the breech of the gun, whereby the character of the gas is changed from CO to C02.

Previous to and since the application of the devices here in question there have been instances of flarebacks in the United States Navy.

October 31, 1903, the Navy Department issued an order providing against danger from flarebacks, as follows:

*“*Special Order No. 44.

“ Navy Department,

“ *Washington, October SI, 1903.*

“ The attention of commanding officers and of all officers and others in charge of guns is directed to the danger from the issue of flaming gases from the breech of large guns when opened quickly after firing. Instances during recent target practice have been reported where, upon opening the breech to load, flames have issued forth of such volume and temperature that the hair and clothing of members of the gun’s crew were singed and scorched. This was observed to be specially liable to occur when firing to windward in a strong breeze.

*625“ Whenever the conditions are such as to create a probability of accident from this cause, the commanding officer and those in charge of the gun will carefully guard against accidental ignition of the powder charges in the vicinity of the gun; and in turret guns, when firing into the wind, special caution must be observed not to hoist a charge for the next round above the turret floor until the breech is open and danger of ignition by flame from the breech has disappeared.

“ Chas. H. Dabling,

*“Acting Secretary A'*

April 13,1904, there occurred a flareback upon the U. S. S, • Missouri, resulting in the death of 5 commissioned officers and of 29 noncommissioned officers and seamen and the serious injury of 2 others — all who were in the turret where the disaster occurred.

Following the report of the *Missouri*accident, May 31, 1904, Special Order No. *57*was issued by the Navy Department, as follows:

“ Special Order No. *57*

“ Navy DepaetmeNT,

“'Washington, *May 31,1904-*

“ Supplementing Special Order No. 44, dated October 31' last, the following instructions are issued for the guidance of the naval service:

“ 1. Recent experience in target practice has demonstrated that there is present in the chamber of all guns an inflammable gas which, under certain conditions, may constitute a danger in igniting the exposed charge while the gun is being loaded for the next round.

“ 2. The sponging of all broadside B. L. guns using cartridges that are unprotected by metal cases is deemed to be necessary. In case of guns of this class, the combined sponge and rammer will be used, with the bristle head dampened with water. The sponge will be entered in the chamber immediately following the shell, and will be shoved home as far as the shell, when seated, will permit, and then will be withdrawn. When the gun is sponged in this manner, it is not possible for inflammable gases or bits of burning powder bags to remain in the powder chamber to endanger the ignition of the charge.

“ 3. In the case of large-caliber guns, where sponging the chamber is impracticable, the danger from ‘ flarebacks,’ or from the presence of inflammable gases or bits of burning material in the bore after firing, must be avoided by making *626sure that all parts of the bore are clear before the charge for the succeeding round is hoisted above the turret floor. In order to make sure that all danger of a premature ignition of a charge while being loaded has passed, a sufficient-interval of time must be allowed to elapse after the breech plug is opened for the gas and smoke in the chamber and bore to dissipate; and the ammunition car shall not be hoisted to the loading position until after it has been determined, by a careful inspection, that no burning residue remains in the chamber and that á clear view through the gun shows the chamber and bore to be free of gas.

“ 4. When adequate mechanical means have been fitted for the purpose of prompty clearing the chamber and bore of all gas, fragments of powder bags, etc., and when, after satisfactory trials, the same shall have been approved officially by the department, the foregoing precautions may be dispensed with; but in no case will any of the precautions be omitted while using any extemporized blowing appliance or when the approved appliance is not working at the standard pressure for which it was designed.

“ 5. The sponging of guns using fixed ammunition where the cartridge bag is protected by metal cases is not deemed to be necessary, but before stowing the empty cartridge cases below steps must be taken to free them from all inflammable gases. This can best be done by laying the cases on their sides, and by testing each one for the presence of gases, by inserting a lighted taper in each case as far as the bottom, thus setting fire to any inflammable gases, consuming them.

“ 6. Under no circumstances shall the material of the cartridge bags or strengthening tapes be added to without authority. Should it be necessary to stiffen the charges, additional tapes will not be used, but, if necessary, the old tapes will be retied or replaced by new tape.

“ 7. The magazine flap doors of only such magazines as are being used to supply charges shall be open, the flaps in all cases being down except during the time of actual passage of the sections of the charge through the door.

“ 8. There shall not be exposed (removed from the tanks) at one time in all the magazines in use more than one charge for each ammunition hoist, and then only as necessary to supply the demand in the handling room; nor shall there be permitted at any time an accumulation of exposed sections for more than one charge for each ammunition hoist outside the magazines in the handling room.

“ 9. A. copy of this order shall be posted in every turret, and commanding officers of all vessels, in acknowledging receipt of the order, will report that this provsion has been *627complied with and that all line officers attached to the vessel have noted and initialed the order.

“ William H. Moody,

“Secretary.”

This order is still in force in the service, and no modification thereof has occured since the use of the devices in question in this suit.

XI. After the construction and tests of the gas-expelling device, which was installed upon the 8-inch gun at the Washington Navy Yard, under the direction of the bureau, the bureau proceeded to direct changes and modifications in various features of the devices which were constructed and installed upon the ships_ for service, in order to render said devices more efficient in their practical operation, and such changes and modifications covered a considerable period of time. Tests were also conducted to ascertain the defects of said devices in their actual operation, from which it was discovered that certain backward or rearward eddies occurred under certain conditions, which tended to convey gases or unconsumed particles of powder bags into the turrets, thereby producing a dangerous condition.

On July 5, 1907, a fatal accident occurred in one of the turrets of the Georgia, notwithstanding the air blast was turned on and the gas-expelling device operating. The guns of this ship were equipped with gas-expelling devices of the kind and character as those which the bureau had supplied to the ships in service, the same representing the improvements and developments of the type of device which was originally applied to the 8-inch gun at the Washington Navy Yard.

The operation of the gas-expelling device in use in the Navy not having proved altogether efficient or satisfactory, a special turret board was appointed after the accident on the *Georgia*to investigate the subject of increasing the efficiency of the devices for expelling gases from the bore, and to report and recommend such changes as appeared to be necessary to increase the safety of conditions in gun turrets. Such board in its report, dated September 19, 1907, recommended the system of putting the gun turrets under special air pressure (the closed-turret method) in addition to and

*628in combination with the use of the gas-expelling device, in ■order to increase the safety to the men in the turrets and to facilitate the expulsion of the gases from the bore of the gun after firing.

The present gas-expelling device, which is the subject of inquiry in this suit, has not accomplished the reduction of the loading interval between the shots of turret guns below that achieved by the use of some of the devices formerly applied. In using some of the appliances employed prior to the device now in question a rapidity of firing was attained which has not been since surpassed.

XII. The devices disclosed by the patents in suit operate to deliver the blast of compressed air into the screw box of the gun, and this air enters the bore of the gun as soon as the gas check is unseated in the process of opening the breech.

Prior to the applications for the patents in suit, the use of compressed air introduced into the gun as soon as the breech was opened enough to permit it to enter, for the purpose of expelling gases and smoke from the bore after firing, had been embodied in devices used in the naval service.

These devices operated to convey compressed air through a pipe having a nozzle which was inserted into the breech of the gun or into the clearance spaces between the breechblock and the screw box as soon as the block was sufficiently opened to permit the air to enter. The most advanced type of these devices was that known as the “ *Illinois*device,” which was installed in November, 1903, and used in the target practice of 1904, with satisfactory results. It differed from the other devices previously improvised in that it was capable of use by inserting the curved nozzle into the blanks or clearance spaces of the screw box as soon as the breechblock was slightly withdrawn, thus enabling the air to rush forward and enter the bore upon the unseating of the gas check. No flarebacks were experienced with the use of this device.

The clearance spaces between the breechblock and the screw box of the naval guns are approximately as follows: In the 8-inch guns, about 11 square inches; in the 10-inch, about 17 square inches; in the 12-inch, about 23 square inches; in .the 13-inch, about 27 square inches. These clearance spaces constitute an ample area within the screw box for the admission *629of sufficient air into the bore as soon as the gas check is unseated to clear the bore of smoke and gases. A greater volume of air can be thus introduced into the bore by the introduction of the same through these clearance spaces than can be introduced through the small radial holes employed in the structure shown by the patents in suit. The device in question in this suit does not permit of the introduction of the compressed air into the bore until the gas check has been unseated, and in this respect involves no invention over earlier devices for accomplishing the same purpose.

Wien the gas check is unseated and free from the bore, the passage for air forward through the bore is approximately four times as great as the passage for air rearward through the clearance spaces existing between the inner wall of the screw box and the circumference of the breech plug. In an 8-inch gun the area of the air passage through the bore is 50.26 square inches, while the area of the passage for air rearward through the screw box is only 11 square inches. The corresponding ratio between the area of the bore and that of the passage for air rearward through the screw box exists in reference to guns of larger caliber, from 8 to 13 inches, respectively.

XIII. Immediately following the explosion of the charge the gases in the bore generated thereby are at a high pressure, but as the projectile leaves the bore it produces a suction, and immediately thereafter the gases, if any are left in the .bore, have reduced in pressure to normal or atmospheric pressure.

At the time when the gas check could be unseated, as near as can be determined, the temperature of the gases in the bore after firing, when smokeless powder is used, is not greatly, if any, in excess of 100° centigrade. The temperature at which CO gas ignites is 650° centigrade. It appears that CO gas is left in the bore in varying quantities after firing when black, brown, and smokeless powders are used. It does not appear from the evidence that what is commonly known as a flarefcack is produced by the ignition of the CO gas left in the bore after firing, caused by its contact with the O of the air in the turret or which enters the bore after the uas check is unseated. This CO sas'left in the bore does *630not reach the temperature at which it would ignite unless there were present at the same time a spark whose ignition temperature is much higher, frequently as much as 1,000° centigrade.

The conditions which may occasionally exist in the guns after firing, due to the presence of CO or other deleterious gases, sparks, and unconsumed particles, and the danger to the men in the turrets incident thereto are analogous to the conditions which exist in a furnace with imperfect combustion and the resultant danger of flames bursting into the fireroom and endangering the stokers when the fire door is opened.

XIV. The state of the art at the date of the patents in suit is indicated by the following patents, whose specifications, drawings, and claims are made a part of these findings:

British patent to Clark, No. 3038, provisional specification filed August 30, 1875, Decker Exhibit 1.

British patent to Johnson, No. 975, provisional specification filed March 7,1881, published September 7,1881, Decker Exhibit 2.

British patent to Vavasseur, No. 4817, provisional specification filed February 26,1898, complete specification accepted January 7, 1899, Decker Exhibit 3.

British patent to Bessemer, No. 1868, provisional specification filed August 25, 1854, complete specification filed and liublished February 24, 1855, Decker Exhibit 4.

British patent to Matthews, No. 2574, provisional specifica-. tion dated February 4, 1896, complete specification filed November 4, 1896, and accepted December- 12, 1896, Decker Exhibit 5.

British patent to Dawson, No. 28785, provisional specification dated December 31, 1903, complete specification filed October 24, 1904, and accepted December 15, 1904, Decker Exhibit 6.

United States patent to Emery, No, 772345, applied for March 3,1901, issued October 18,1904, Decker Exhibit 7.

United States patent to Perino, No. 68220B, applied for March 16,1901, issued September 10,1901, Decker Exhibit 8.

United States patent to Browning, No. 543567, applied for April 16,1895, issued July 30,1895, Decker Exhibit 9.

*631United States patent to Boucher and McCloskey, No. 759803, applied for February 8, 1904, issued May 10, 1904, Decker Exhibit 10.

United States patent to Spiller, No. 457293, applied for October 3, 1889, issued August 4, 1891, Decker Exhibit 11.

United States patent to Maxim, No. 436899, applied for April 8, 1890, issued September 23, 1890, Decker Exhibit 12.

United States patent to Johnsen, No. 160101, applied for November 30, 1874, issued February 23, 1875, Decker Exhibit 13.

United States patent to Baldwin, No. 484774, applied for October 10, 1891, issued October 25,1892, Decker Exhibit 14.

United States patent to Serve, No. 562493, applied for July 10, 1894, issued June 23, 1896, Decker Exhibit 15. See also “ Defendant’s Exhibit Serve Model, Decker No. 5.”

United States patent to Miller, No. 47118, applied for April 4,1865, issued April 4,1865, Decker Exhibit 16.

United States patent to Leech, No. 732359, applied for August 26, 1902, issued June 30,1903, Decker Exhibit 17.

United States patent to Simmons, No. 241433, applied for October 7, 1880, issued May 10, 1881, Decker Exhibit 18.

United States patent to Fox, No. 286692, applied for February 19,1883, issued October 16, 1883, Decker Exhibit 19.

United States patent to Smith, No. 790664, applied for February 20, 1904, issued May 23, 1905, Williams Exhibit 1.

British patent to Ager, No. 1852, provisional specification dated July 14, 1866, complete specification dated and published January 14, 1867, Defendant’s Exhibit Ager Patent, Decker No. 1.

British patent to Ager, No. 152, dated January 17, 1866, Defendant’s Exhibit Ager Patent, Decker No. 2.

XV. Upon the foregoing findings of fact the court finds the ultimate facts, so far as they are questions of fact, that the devices involved in the patents in suit were conceived by officers in the Bureau of Ordnance and were worked out and tested at the expense of the Government in the Washington Navy Yard by subordinates under the direction of the Bureau of Ordnance, Navy Department, thereby giving the defendants what is known as a shop right or license to use said devices or patents, or either of them, on any guns in *632the United States Navy; that the patent of Sawyer is anticipated by that of Knapp and Dunn, so developed and tested under the bureau as aforesaid, by reason of all which no implied contract arises to make compensation therefor.

*Mr. Benjamin Micou*and *Mr. Ernest WilMnson*for the claimant. *Herbert db Micou*and *WilMnson, Fisher db With-erspoon*were on the brief.

*Mr. Malcolm A. Coles*(with whom was *Mr. Assistant Attorney General Jdhn Q.*Thompson) for the defandants.

Peelle, Ch. J.,

delivered the opinion of the court:

This action is to recover royalties for the alleged use by the Navy Department of patents issued to the claimant, trustee, on applications theretofore made by his assignors, Frederick J. Sawyer and John J. Knapp and George *W.*Dunn, for blowing out of the bore of guns inflammable and deleterious gases remaining in the gun after firing.

The substantial and controlling facts found are these: Prior to the applications for the patents for the use of which royalties are claimed there had been serious accidents from the explosion of gases remaining in the guns after firing. A suggestion was made in the communication set forth in Finding III to the Bureau of Ordnance, having to do therewith, of a device to extract gases from the bore of guns passing out through the muzzle, thereby preventing them from escaping into the turret while the breechblock was being opened. The communication was referred by the bureau April 11, 1904, to the Washington Navy Yard, where Lieut. Commander Knapp was on duty, requesting an investigation of the method suggested, which was done under the direction of Foreman Lynch, under whom Master Mechanic Dunn, a civilian employee, was then serving.

Two days later news of the accident on the *Missouri*reached the Bureau of Ordnance, and on April 13, 1904, the chief of the bureau had a conference on the subject with Lieut. Commander Chase, assistant to the bureau, who suggested a plan for preventing such occurrences. The afternoon of that day Chase, together with Latimer, designed a' *633means of expelling gases from the bore of guns by the use of a cleaning medium — air, or air and water, or steam — to be led into the screw box through radial holes drilled into the blank spaces thereof so that the cleaning medium would enter the bore as soon as the gas check was unseated in the process of opening the breech for a reloading, substantially the same as disclosed in the patents in this suit. r

The means so designed by Chase and Latimer were communicated to Lieut. Commander Knapp and Master Mechanic Dunn at the navy yard on the morning of April 14, 1904. The plan so suggested by Chase was installed and tried on an 8-inch gun from the Iowa, then at the yard, and operated successfully as early as May 13, 1904, 12 days before Sawyer filed his application for patent May 26,1904.

Latimer by direction of Chase indicated to Knapp how the radial holes could be drilled through the breech of the guns and into the blank spaces of the screw box, and suggested to Knapp that the plan be tried by application to a dummy breech mechanism which was then in the gun shop. Master Mechanic Dunn was present during part of the conversation between Knapp and Latimer, but neither Knapp nor Dunn made any claim that they or either of them had made a gas-expelling device of a like or similar nature to the one designed and suggested by Chase and Latimer.

F olio wing these conversations and suggestions, seven days thereafter Knapp, in the line of his duty and over his official signature, submitted to the superintendent of the navy yard a memorandum and sketch of a description for extinguishing burning matter in the bore of a gun and also preventing blowbacks, and requested that an 8-inch gun from the *Iowa*be utilized to test and develop the device; and the use of an 8-inch gun from the *Iowa*theretofore authorized for the like or same purpose was continued.

While the work was going on Chase and Latimer visited the yard and, in the presence of Knapp and Dunn, directed modifications and changes in the device, no claim then being made by Knapp or Dunn that they, or either of them, had originated a like or similar design; nor did the chief of the bureau, Chase, or Latimer have any knowledge that Knapp and Dunn claimed to have originated the device until their *634patent attorney, Mr. Church, visited the bureau on or about July 16, 1904, and asked the bureau to request the Patent Office to expedite the examination of the application for patent then pending, which the bureau declined to do on the ground that it considered that subordinates under its direction had designed the device in question.

Following the visit of Mr. Church to the bureau as attorney for Knapp and Dunn, Chase and Latimer visited the navy yard, and Latimer there insisted that he had disclosed to Knapp and Dunn the plan of constructing the gas ejector on April 14, 1904, and they were informed that the device had been previously designed by Chase and Latimer in the bureau.

Coming now to the patent claimed by Lieut. Sawyer, who made application therefor May 26, 1904 — no caveat having been previously filed — it appears that prior thereto (Apr. 24, 1904) Lieut. Commander Bristol submitted to Chase, assistant to the bureau, a scheme for an air jet substantially like that theretofore suggested by Chase and Latimer. Soon thereafter Lieut. Sawyer, then attached to the Nevadavis-ited the Brooklyn, on which Lieufij Bristol was. serving,, and Bristol explained and illustrated to him the design which he had conceived and disclosed in a letter to Chase. Thereafter, on May T, Lieut. Sawyer visited Washington to consult Ernest Wilkinson, Esq., a patent attorney, about filing an application for a patent for “improvements in means for sponging out guns.” Sawyer’s application, as before stated, was filed May 26,1904, but prior thereto, May 18, the gas expelling device installed on the 8-inch gun from the *Iowa*under the direction of the Bureau of Ordnance was practically completed and was in successful operation. The application of Knapp and Dunn was filed June 10, 1904, for the invention which they claim to have made April 14, but the invention of substantially the same character of device was made by Chase and Latimer on the afternoon of April 13, and was disclosed to Knapp and Dunn by Latimer, as before stated, on the morning of April 14.

Pending the applications of Sawyer and Knapp and Dunn, Knapp became suspicious that Sawyer had anticipated the *635device which he claimed he and Dunn had conceived, and apparently to avoid interference in the Patent Office they entered into the agreement -set forth in Finding YII by Paragraph IX of which it was agreed that the question of priority of invention between them should be submitted to their respective patent attorneys, Wilkinson and Church, and by them, if they failed to agree, to an arbitrator, whose decision should be final; but the question was not determined,, and apparently in lieu thereof a short time before the issuance of the patent the Knapp and Dunn application was canceled, and by amendment was incorporated into the Sawyer application, thus endeavoring to avoid any probable interference between the applications in the Patent Office and at the same time giving to the Sawyer patent the broader claims of the Knapp and Dunn application.

On August 15,1904, the claimant, trustee, by his attorneys, while the applications for patents were pending, presented for the first time by letter his claim against the Government for compensation for the use of the device claimed to be covered by the patents in suit, conceding therein that the same had been tested by the United States. The correspondence in relation thereto is set forth in Finding IX.

In response to the communication the Secretary of the Navy informed the claimant, through his attorneys, that the invention for which compensation was claimed had been inspired and developed under the direction of the Bureau of Ordnance by its own subordinates, among whom were Lieut. Commander Knapp and Mr. Dunn, and that, therefore, the department would authorize the bureau to use the device, leaving the question of compensation, if letters patent should be issued, to the determination of the courts, to which the claimant, through his attorneys, replied that he was content that the Navy Department should proceed with the manufacture and use of the device, leaving the courts, if letters patent should be granted, to determine the compensation to be paid.

The claimant’s contentions are (1) that the title to the patent is in the claimant; (2) that there was a contract to pay royalties if the Government used the device, and that, *636therefore, the court has jurisdiction; (3) that the Government had used the device as covered by the patents and is, therefore, liable for royalties.

The defendants’ contentions are (1) that the claimant acquired title, if at all, by assignments, and that, therefore, under Revised Statutes, sections 3477 and 3737, inhibiting assignments of claims and contracts, he can not maintain this action; (2) that the facts respecting the relation of the parties shown by the correspondence set forth in Finding IX are not sufficient upon which to base an implied contract; (3) that prior to the date of Sawyer’s application, May 26, 1904, substantially the same means for expelling gases from the bore of guns had been conceived and invented by others and reduced to successful practice 12 days prior to the date of Sawyer’s application; (4) that Chase, Latimer, Knapp, and Dunn were subordinates of the Bureau of Ordnance, and that before the device was invented by Knapp and Dunn, as they claim, it was installed at the Washington Navy Yard, under the direction of the bureau, by Government officials in the line of their duty, and that, therefore, the Government has a shop right or license to use the same; and (5) that the Sawyer patent is anticipated by the prior art and therefore, lacking in invention, and is void.

Assuming, as we think we may, that under the assignments made while the applications for patents were pending, as set forth in Finding VII, and before the claim herein arose, the claimant, as trustee, may maintain this action *[Berdan Fire Arms*Co., 25 C. Cls., 355; *Federal Manufacturing Co*., 42 C. Cls. 479, 511; *Campbell*v. *James,*18 Blatchford, 92; and Revised Statutes, sec. 4898), we will inquire (1) has the court jurisdiction to entertain the action, i. e., can a contract be implied from the- facts established to maké compensation for the use of the patents; (2) who invented the device for which royalty is claimed; (3) has the Government a shop right or license to use the patent.

The questions in relation to the origin of the invention and its use are so interwoven with the contentions of’the parties in the correspondence relied upon by the claimant to establish an implied contract that we will consider them substantially in the order in which they arose.

*637Broadly speaking, it was not only .within the province of the Chief of the Burean of Ordnance but it was clearly within the line of his duty to devise or cause to be devised such means, methods, or devices as in his judgment were essential and necessary not only to make the guns of the Navy efficient, but to see that they were used in a way to protect life and property. With this keen insight, and endeavoring to profit from the accidents which had theretofore occurred after the firing of guns, the Chief of Ordnance, before the filing of either of the applications for the patents .in suit, directed the officers in the Washington Navy Yard to investigate the method suggested to it for drawing smoke from the chamber and bore of guns, and to experiment with the device fitted for the use of both air and water ejector. The bureau’s direction, as set forth in Finding III, was copied and distributed before the experimental work was commenced, and was presumably known to all the officers on duty in the navy yard having' to do therewith, including Lieut. Commander Knapp and Master Mechanic Dunn, as the former was then on duty in the yard as inspector of ordnance, guns, and mounts, while Dunn was under Foreman Lynch, who directed the work in question to be done.

The question of novelty or invention, the courts have held, is a question of fact to be determined upon the evidence adduced. *(Reckendorfer*v. Faber, 92 U. S., 347, 352; *American Sales Book Co. et al.*v. Bullivant, 117 Fed. Rep., 255, 258.)

“ The first to reduce an invention to practice, as shown by an actual construction produced in court, is usually held to be the inventor as against another who merely says he had' previously conceived the invention.” *(Merrimac Mattress Co.*v. Feldman, 133 Fed. Rep., 64; *Laas et al.*v. *Scott et*al., 161 Fed. Rep., 122, 126; *Warren Bros. Co.*v. *City of Owosso,*166 Fed. Rep., 309, 315.)

In the .case of *Agawam Co.*v. *Jordan*(7 Wall., 583, 602) it was said: “The settled rule of law is that whoever first perfects a machine is entitled to the patent and is the real inventor, although others may have previously had the idea and made some experiments toward putting it in practice. He is the inventor and entitled to the patent who first *638brought the machine to perfection and made it capable of useful operation.” To the same effect also are the cases of *Laos et al.*v. *Scott et al.*(161 *Fed. Rep.,*122, 126) and *Warren Bros. Co.*v. *City of Owosso*(166 Fed. Rep., 309, 315.)

“ It is not necessary in order to establish reduction to practice that the test [of the device relied upon] should be one of complete accuracy. It is seldom that an inventor reaches perfection in the first device constructed. The test should be to ascertain whether the device reasonably meets the requirements of the specifications, and, if it does not measure up to this test, can it be made to meet it by the introduction of mere mechanical changes? If it can, it should be regarded as a reduction to practice.” *(Poole*v. Dunn, 151 O. G., 450.)

In the case of *Buser et al.*v. *Novelty Tufting Machine Co.*(151 Fed. Rep., 478, 492) the court, referring to what constitutes an experiment or a completed invention capable of producing the result sought to be accomplished, said: “ If, however, the machine or other thing is complete, and capable of producing the result sought to be accomplished, it has passed the experimental stage and becomes an invention; and, in order that it may constitute an anticipation, it is immaterial how well it becomes known or how much it is used.” Further in the case cited it was said: “ The prior knowledge and use by a single person is sufficient. The number is immaterial.” (See also *Walker on*Patents, §71, and cases therein referred to.)

In the case of *Agawam Co.*v. *Jordan {supra,*p. 603) it was further held, in substance, that persons employed were entitled to their own independent invention, “ but where the employer has conceived the plan of an invention and is engaged in experiments to perfect it no suggestions from an employee not amounting to a method or arrangement, which in itself is a complete invention, is sufficient to deprive the employer of the exclusive property in the perfected improvement.” (See authorities cited therein and also cases of *Collar Co.*v. *Van Dusen,*23 Wall., 530, 563; *Atlantic Works*v. *Brady,*107 U. S., 192; *Fuller & Johnson Mfg. Co.*v. *Bartlett,*68 Wis., 73, 85.) •

*639In the case of *Solomons*v. *United States*(22 C. Cls., 385, 342) the court said: “ Upon the facts now found the court is of the opinion that where an officer of the Government is properly assigned to the task of devising, preparing, or making an instrument, implement, or other subject of manufacture for the public service, and he does so, the Government bearing the expense of the experiments incidental to the invention, and the cost of completing, perfecting, and testing the device, the officer receiving his salary for his services, a presumption of implied contract does not arise, and no action to recover a royalty for the use of the invention can be maintained.” The authorities cited seem to cover the present case respecting the Knapp and Dunn patent.

Sawyer filed his application May 26, 1904, and that is the date of his invention, according to the ruling in *McCormack*v. *Cleal*(12 App. D. C., 335), hereinafter referred to, while Knapp and Dunn did not file their application until June 10, 1904,- both applicants seeking by similar, if not by like plans, to accomplish the same results.

Doubtless, to avoid the effect of a decision in the Patent Office on the question of interference, the claimants entered into the agreement set forth in Finding VII, whereby the question of the priority of the invention, it was agreed, “ shall be submitted ” (par. 9) to their respective patent attorneys who, on their failure to agree, it was provided “ shall be referred to an arbitrator ” whose decision “ shall be final.” But, for obvious reasons, no such decision appears to have been rendered. The Patent Office appears to have treated the agreement as relieving it from raising the question, though clearly it had the right, if it was not its duty, under Revised Statutes, section 4904, to do so. (See *Sherwood*v. Drewson, 124 O. G., 1205.)

In the case of *Morgan*v. *Daniels*(153 U. S., 120) it was in substance held that where the priority of an invention was in question before the Patent Office and a decision was rendered in respect thereto the same was controlling upon a question of fact in suits between the same parties unless the contrary should be established by testimony which in character and amount carried thorough conviction.

*640The omission or neglect of the Patent Office to raise and decide the question, however, does not preclude the court from inquiring into the matter. (Walker on Patents, sec. 142, and cases therein referred to.) It seems clear that had the Patent Office gone into the question, under the section of the Kevised Statutes cited, as well as under its own rules and decisions, the decision would have been in favor of Knapp and Dunn. That is, that the patent of Sawyer was anticipated by that of Knapp and Dunn, who had tested and developed the same at the expense of the Government, under the direction of the Bureau of Ordnance. If we are right in this, then the patent of Sawyer, under the authorities we have cited, is deprived of its novelty.

And if we were to assume that Knapp and Dunn were the originators'of the device, they permitted it to be developed, tested, and used at the expense of the Government without any notice to it that they claimed any property therein until after they had applied for a patent. On this theory the case is ruled by that of *Gill*(25 C. Cls., 415, 423), where, in substance, it was held that if ah inventor took advantage of his connection with the Government to introduce his unpatented device into the public service, without intimation that he claimed property therein or that he intended to protect the same by letters patent, and allowed the Government, as in effect conceded by the claimant in his letter demanding compensation, to apply and test the same at its own cost and risk by bringing it into practical use before he applied for a patent, no contract could be implied to pay therefor; and that such rule would extend to a machine constructed after a patent had issued, if used in the place and business In which the inventor voluntarily placed his device. On appeal the case was affirmed (160 U. S., 426), and in addition it was there ruled that “ a person looking on and assenting to that which he has power to prevent is precluded from afterwards maintaining an action for damage.” (See *Solomons*v. *United,*States, 137 U. S., 342, also affirmed, and other cases therein cited to the same purport. See also the case of *McClurg et al.*v. *King stand et al.,*1 How., 202.) In the latter case it was held that the facts (substantially as in the *641Gill and the present case) justified the presumption of a license to use the invention. To the same effect also is the cases of *Wade*v. *Metcalf*(129 U. S., 202), *McAleer*v. *United States*(150 U. S., 424, 431).

By reason of the acts of the Bureau of Ordnance, coupled with the development and use of the device by and with the consent of Knapp and Dunn, without any intimation that they claimed or intended to claim any property therein until after they had applied for a patent, the correspondence looking to compensation for the use of the device, after the issuance of letters patent, can not be held to create an implied contract. To so hold would be permitting Knapp and Dunn to take advantage of their acquiescence and silence in the development and use of the device at the expense of the Government at a time when they should have spoken. *(Fuller, &c.,*v. *Bartlett,*68 Wis., 73; *Lane & Bodley Co.*v. *Loche,*150 U. S., 193, 201.)

In the first of the cases cited (68 Wis.) the superintendent of a manufacturing company, knowing that it was the intention of the company to put upon the market a new machine, voluntarily disclosed his conception of a device to be used in connection therewith; and under the directions of the company and with its material and at its expense he voluntarily perfected such device and constructed machines and aided in putting them on the market. On the facts stated the court, as stated in the syllabus, “ *Held,*that from the facts the law would not imply an agreement for the absolute assignment to the company of the patent for such device, but would imply an agreement for a license to the company to manufacture perpetually, at its then existing, works, machines embodying such invention, and to sell them wherever it could find a market.”

In the case of *Russell, etc.,*v. *United States*(35 C. Cls., 154), where the Government had entered into an agreement with the Krag-Jorgensen Company to manufacture arms, said company giving bond to indemnify the United States “ for all liability on account of patent rights granted by the United States which might affect that right to manufacture granted by said contract,” the claimants sought to induce the *642Government to adopt their patent, conceding an infringement, on the theory that the bond so executed was for the benefit of the patentees. In response to that contention the department, among other things, said: “ That company agrees to indemnify the United States on account of any patent right granted by the United States which may affect the manufacture of the guns, in which case your course would be to communicate directly with the company. On the other hand, should the Government proceed to manufacture the arms without such arrangement, your course will be to bring a suit against the Government in the Court of Claims after manufacture has progressed.” The court held that no implied contract arose and on appeal the case was affirmed. (182 U. S., 531.)

The *Harley case*(39 C. Cls., 105, 114, affirmed 198 U. S., 229) is later, and is even a stronger case than that of Russell.

There is no language in the correspondence or in the acts of the officers of the Government from which the court can conclude that there was mutual intent to contract. The claimant in his communication to the Secretary of the Navy, after stating that the inventions applied for did not relate to a matter with which either of the claimants’ assignees was directed to experiment as part of his official duty and that the devices had been tested with satisfactory results by the Government, advised the department that further application or use of said inventions was not authorized by the applicants for patents save upon the expectation of a reasonable compensation, to which the Secretary of the Navy replied, in substance, that while the Bureau of Ordnance would be authorized to proceed to manufacture and use the device mentioned, leaving the question of compensation to the courts, the same had been inspired and developed under the direction of the Bureau of Ordnance by its own subordinates in the line of their duty, and that Lieut. Commander Knapp and Mr. Dunn were among the subordinates referred to in the statement or indorsement of the bureau, referring the claimant’s communication to the Secretary.

Here was a denial of the claimant’s right to compensation and the assertion of a superior right on the part of the *643Government to tbe use of tbe device on tbe ground tbat tbe invention for wbicb he claimed compensation bad been inspired by subordinates in tbe bureau, and that therefore the manufacture would be authorized and tbe question of compensation, if any, in case letters patent should be issued, would be for the courts to determine. Certainly it can not be said from the correspondence that there was any mutual intention or understanding that the Government should compensate the claimant for the use of said invention.

Implied contracts in fact do not arise from the denials and contentions of .parties but- from their common understanding in the ordinary course of business, whereby mutual intent to contract without formal words therefor is shown. (Hert-*zog*v. Hertzog, 29 Pa. St., 465, and authorities there cited; *Harley*v. *United States, supra.)*

As between the claimant and the Government, the latter is the owner for the purpose of its own use the same as though the device had never been patented. True, the suggestions to Knapp and Dunn, except as to the letter of the chief of the bureau set out in Finding III, were made orally, but this can not be held to aid the claimants since the device so suggested was developed and perfected by them, under the direction of the bureau acting in the line of duty, and any other construction would be far-fetched.

The device itself so patented being the device of the bureau, thereby relieves the case from the rule laid down in the cases cited by the claimant to the effect that suggestions made to a patentee by others to defeat his right to a patent must be such as to furnish all necessary information upon which to enable one to construct the improvement. That is to say, the suggestions must be so full and complete as to leave nothing to devise or work out by his own skill or ingenuity. *(Pitts*v. Hall, 2 Blatch., 229.) However, the suggestions to Knapp and Dunn by the officers of the Bureau of Ordnance had reference only to the device originating in the bureau, which was substantially the device perfected under its direction, and not to any device claimed to have been conceived by Knapp and Dunn, of which the bureau had no knowledge until after they filed their application for a patent.

*644With respect to the Sawyer patent it must be held that his invention dates from the time of the filing of his application, there being no sufficient proof to the contrary. *(The Barbed Wire Patent,*143 U. S., 275; *Drewson*v. *Hartje Paper Mfg. Co.,*131 Fed. Rep., 734; *Eck*v. *Kutz,*132 Fed. Rep., 758.) In the case of *Mergenthaler*v. *Scudder*(11 App. D. C., 264, 278) it was held that “ The fact of conception by an inventor, for the purpose of establishing priority, can not be proved by his mere allegation, nor by his unsupported testimony, where there has been no disclosure to others or embodiment of the invention in some clearly perceptible form, such as drawings or model, with sufficient proof of identity in point of time. For otherwise such facile means of establishing prioritjr of invention would, in many cases, offer great temptation to perjury, and' would have the effect of virtually precluding the adverse party from the possibility of rebutting such evidence. Hence it has been ruled in many cases that the mere .unsupported evidence of the alleged inventor, on an issue of priority, as to the fact of conception and the time thereof, can not be received as sufficient proof of the fact of prior conception.” *(Bates*v. *Coe,*98 U. S., 31, 34; *Eck*v. *Kutz,*132 Fed. Rep., 758; *Hisey*v. Peters, 6 App. D. C., 73; *Stevens*v. *Putnam,*18 O. G., 520; *Farmer*v. *Brush,*17 O. G., 150; *Brungger*v. *Smith,*62 O. G., 1511.) That seems to cover this case, and we see no reason why under the facts it should not apply here. (12 App. D. C., 335.)

Especially are we of this opinion, since the acts of the parties by their agreement and 'the transference of the broader claims of the Knapp and Dunn application to that of Sawyer were manifestly to avoid not only the status of Knapp and Dunn in their relation to the Bureau of Ordnance but as well the action of the officers of said bureau in their prior conception of the device so patented. The prima facie presumption of the patentability of the device arising from the letters patent issued to Sawyer is overcome by the convincing proof of the prior conception and use of substantially the same device by Knapp and Dunn so suggested, developed and used, as aforesaid.

Sawyer is the only one who testifies, and he orally (without either model or drawings disclosing his device), as to the *645date prior to his application that he conceived the device so patented; but prior to his conception, as claimed, others had discussed the possibility of boring holes radially in the breech of a gun, as shown in Finding II.

Some days prior to the filing of the application by Sawyer for a patent he was informed by Bristol of a device he had conceived, a drawing of which he had sent to Chase April 27, 1904, and which he explained and illustrated to Sawyer, as set forth in Finding V. True, Sawyer at the time stated to Bristol that he had a scheme to prevent such accidents which was different from his, but in what particular he did not disclose either by word, model, or drawing; and on or about May 7, 1904, he came to Washington and- consulted with a patent attorney relative to filing an application for a patent, which was filed May 26,1904. Sawyer seemed to understand the plan thus shown him by Bristol, for he claimed to have a scheme which was different therefrom; and if so, he may fairly be classed as one sufficiently skilled in the art to comprehend the mechanical details essential to the construction of the device into a completed form for effective service. *(Aron*v. *Manhattan Railway Co.,*132 U. S., 84, and cases there cited. See also the case of *Pope Mfg. Co.*v. Gormully, 144 U. S., 248.)

This being true, it must be held that the patent of Sawyer was anticipated by the patent of Knapp and Dunn, if not by Bristol, the device for which was conceived by Chase and Latimer and was developed and tested by Knapp and Dunn, as aforesaid, under the direction of the Bureau of Ordnance. Therefore, notwithstanding the correspondence between the claimant and the Bureau of Ordnance respecting the use of said patents, no implied contract arises to make compensation therefor.

We deem it unnecessary to further consider the lack of novelty in the Sawyer patent, or to consider more specifically the claims in the Knapp and Dunn and the Sawyer patents— all of which are made part of the petition — as we are now concerned with the question whether an implied contract arises to make compensation for the use of patents; and what we have said along that line has been with reference thereto. That is to say, we have construed the language of the *646correspondence in connection with the conception of the device by Bristol, Chase, and Latimer and the action of the Bureau of Ordnance in the development and test thereof, which is substantially the device so claimed to have been conceived by Sawyer, as otherwise the patent of Sawyer so anticipated by the Knapp and Dunn patent would be left standing alone in the correspondence.

Whether the patents in suit are lacking in invention, and therefore void by reason of the prior state of the art disclosed by Finding XIV, we will not now consider, nor have we drawn any conclusion therefrom in the findings other than the final conclusion that the claimant is not entitled to recover and the dismissal of his petition therefor. This was in effect the course pursued by the court in the case of *Harley*v. *United States,*supra, and this applies to the patent of Sawyer as well as to that of Knapp and Dunn.

It results that the claimant’s petition must be dismissed, which is accordingly done.

Howey, <T., was not present when this case was tried and took no part in the decision thereof.