28th CONGRESS,
2d Session.

Doc. No. 127.

HO. OF REPS.
War Dept.

COLT'S SUBMARINE BATTERY.

LETTER

FROM

THE SECRETARY OF WAR,

RELATIVE TO

The secret of Colt's submarine battery.

MAY 15, 1844.

Referred to the Committee on Naval Affairs.

FEBRUARY 8, 1845.

On motion of Mr. McKay,

*Ordered,* That the report of the Secretary of War, made on the 15th of May last, in answer to the resolution of April 19, 1844, as to whether the combustible agent used by Mr. Colt in his submarine explosion was a secret before he made the same known at the seat of government, be printed.

WAR DEPARTMENT, May. 8, 1844.

SIR: I have the honor to acknowledge the receipt of a copy of the resolution adopted by the House of Representatives on the 19th of the last month, directing the Secretaries of War and the Navy "to communicate the fact, whether the combustible agent used by Mr. Colt was a secret before he made the same known at the seat of government, and whether the mode of its application to harbor defence be new; and, if new, what objections there are to its adoption, if objections do exist."

The subjects embraced by this resolution, and submitted to the consideration of this department, necessarily occasioned an examination and inquiries productive of the delay which has occurred in rendering the required report.

Public attention has been directed, for some time, to the experiments of Mr. Colt, and it is presumed that the nature of the agents which he employs is well understood. As no special communication, such as is supposed in the resolution of the House, had been made to the War Department, with a view to enable Mr. Colt to point out what he considered novel in his means and appliances, I addressed him a letter; the reply to which, with a previous note from him, is hereto appended. It will be perceived, too, by the reply, herewith transmitted, from the honorable the Secretary of the

Blair & Rives, print.

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Navy, to my letter addressed to him on the 7th instant, that Mr. Colt has been so guarded and cautious in his communications with that department, as to keep from us all light and explanation as to his combustible agent, and the means of its employment.

For the purpose of being put in possession of the views of the appropriate department in regard to the question of "harbor defence," the resolution was referred for report to Colonel Totten, the able chief of the corps of engineers. His full and lucid reply, examined and sanctioned by the experienced and scientific officers at the head of the Topographical and Ordnance Bureaus, is hereto appended.

With a desire, also, to bring the judgment of men of general science to bear upon the subject, and especially to obtain their opinions and facts in reference to the alleged "secret," and pretended originality of invention by Mr. Colt, I addressed letters, covering copies of the resolution of the House, to Professors Hare, of Philadelphia, and Henry, of Princeton. Their replies, as well as a letter from Dr. Thomas P. Jones, of Washington, referring to Professor Hare's communication, are hereto annexed.

The protest of Mr. Colt, to be found in his letter addressed to me on the 22d ultimo, and his suggestions as to the reply to be made by this department, I have, of course, under a view of the resolution of the House, felt it my duty to disregard.

It is generally understood that gunpowder is the explosive agent used by Mr. Colt, and that galvanism is employed to fire it; that harbors are to be defended by deposits of gunpowder fired at will, and at a distance, by the aid of galvanism. In regard to the use of these means, the communications just referred to establish conclusively the following points:

1st. That as respects the employment of a galvanic current to ignite a wire, and, by that means, to fire simultaneously numerous charges of gunpowder, it was applied by that distinguished professor, Dr. Hare, of Philadelphia, as early as 1833, to rock-blasting, and proposed as a means of defence.

2d. The idea of making this use of galvanism did not originate with Mr. Colt; and its successful application to submarine explosions was made by Colonel Pasley, Mr. Roberts, Mr. Paris, and others, before Mr. Colt's projects were submitted to the public.

3d. That the suggestion to apply to harbor defence deposits of gunpowder, to be fired by galvanism, flows so naturally from the use of that agent in producing submarine explosions at a distance, that no novelty can be assumed for the idea; and that it is, in fact, merely an application of the agent, galvanism, to fire Fulton's stationary torpedoes. The proposal to defend harbors by deposits of gunpowder is not novel, nor is it novel to fire such deposits beneath the water by galvanism.

4th. That even if novelty could be claimed for this mode of harbor defence, it is liable to fatal objections as a primary means of that object; and, as an auxiliary means, to very strong objections. The precise position of a vessel, by day and night, cannot be ascertained by the operator who controls the galvanic battery, so as to produce the explosion at the moment when it will be effective. The arrangement of the wires for transmitting the galvanic current may easily be destroyed. The operator must be protected by a fortification, or by an army, to prevent the destruction of all his means of action by the landing of the enemy. And, whilst upon this point, I may remark, that the very supposition (as stated in Colonel

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Totten's report) of danger to the boats of the enemy, tends to prove the security of their fleet; for, if the magazines were exploded in order to destroy the boats employed in search of the wires, then the fleet would be without cause of fear, and the harbor without defence. The hazard of those boats employed in the search would not be equal to the "forlorn hope" in storming a fortified place, and would, like that, be a regular military duty. But the unprofitableness of blowing up the boats employed in the search would, of itself, make the search a safe duty, and therefore the communications with the magazines would always be found, and the duty of searching for them would be without hazard. Yet, admitting the risk, by special arrangements for that purpose, it is no more than that of a "forlorn hope," and is over with the first boat exposed to it. Other boats can then complete the search, and the destruction of the connecting wires, at leisure, and with impunity.

5th. If the means assumed to be those employed by Mr. Colt (and if we are in error, he has his own caution alone to blame) are actually not those which he uses, then I affirm that any intelligent, scientific person, aided and encouraged by equal munificence and appropriations, could, without invading any patent or exclusive right of others, and by merely applying means which have been gratuitously contributed to science by distinguished men of our country, accomplish all that Mr. Colt has achieved under the bounty and generous encouragement of his government, in his peaceful experiments against a defenceless and untenanted ship.

Whatever may be the claim to merit, on account of the skill and handiwork of Mr. Colt, displayed in his preparations and uninterrupted experiments on the shores of the Potomac, it will probably be acquiesced in by all, that if the expenditure of seventeen thousand four hundred and four dollars and twelve cents ($17,404 12) does not impair that claim to merit, it will, at all events, be considered as a generous encouragement to the exercise of his talents.

I have the honor to be, sir, with high respect, your obedient servant,

WM. WILKINS,

Secretary of War.

Hon. J. W. JONES,

Speaker of the House of Representatives.

No. 1.

WASHINGTON, April 22, 1844.

SIR: I called on Saturday, in hopes of seeing you regarding a resolution of Congress, calling for information from your department on the subject of my submarine battery; my object being to request that you would reply to said call, by simply reporting the fact that no communication has ever been received at your department from me, on the subject of my new mode of fortification; and that you possessed no further information on the subject, than the natural inferences framed from witnessing his public exhibitions of its effects.

I went to your department to see you again this morning, without success. I therefore am compelled to adopt this mode of communicating with you on the subject, and to urge, as a matter of justice to me, that no com-

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munication shall be sent to Congress from yourself, or any of the bureaus in your department, which shall in any way attempt to explain what they supposed to be my plans of operation.

The relations existing between me and the government, on this subject, are such, that neither the government nor myself has a right to make any of my plans known to the public; and as a communication from either your Ordnance or Engineer Bureaus must inevitably be breaking the good faith of the government towards me, in case they should give any hints which must lead to an exposure of my plans, I am compelled to enter this my most solemn protest against anything being said or reported by your department, except the simple fact that nothing whatever is known to you of the matter.

In haste, I have the honor to be, very respectfully, sir, your obedient servant,

SAMUEL COLT.

Hon. Wm. WILKINS,
Secretary of War.

No. 2.

WAR DEPARTMENT, April 27, 1844.

SIR: I enclose you a copy of the resolution adopted by the House of Representatives, directing the Secretaries of War and the Navy to communicate to that body information in reference to your "combustible agent," or submarine battery.

Although discouraged by the terms of your letter, addressed to me under date of the 22d instant, yet I deem it to be my duty to say to you that I will, at any moment convenient to yourself, receive from you such communications as you may think proper to make explanatory of the objects of inquiry mentioned in the accompanying resolution. Whatever explanations, or whatever facts tending to elucidate your proposed scheme of harbor defence, or your claim to originality of invention, it may be your pleasure to give to this department, shall receive my attention, and shall have bestowed upon them every consideration to which they may be entitled.

I will thank you for a reply as soon as you can conveniently give it.

Very respectfully, your obedient servant,

WM. WILKINS.

MR. SAM. COLT.

No. 3.

WASHINGTON, April 30, 1844.

SIR: I have had the honor of receiving your letter of the 27th instant, acquainting me with your readiness to receive explanations and information respecting my mode of fortifying harbors by submarine batteries, in view of answering the resolution of the House of Representatives requiring information on that subject. While I cordially tender you my thanks for this act of courtesy, I beg leave respectfully to decline furnishing the Department of War with any information upon the subject—for the reason, that it is of the greatest consequence, both to the government and myself, that the material and the mode of constructing and of using those batteries should

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be kept secret; and I have already made full explanations to the Navy Department upon the subject, which are deposited in its secret archives. To communicate these to another department, would, I conceive, not only be unnecessary, but greatly increase the risk of making public matters which it is essential should be kept secret. Should the Navy Department desire any further information, I shall hold myself in readiness at all times to furnish what may be necessary to enable the head of that department to understand the efficiency and value of my invention.

Very respectfully, I have the honor to be, sir, your obedient servant,
SAMUEL COLT.

No. 4.

NAVY DEPARTMENT, May 7, 1844.

SIR: I have received your letter of this date, informing me that you are engaged in the preparation of a report on the subject of Colt's submarine battery.

It appears that there has been paid, under orders from this department, to Mr. Colt, and to his order, by virtue of the joint resolution of August 31, 1842, up to the 22d of November, 1843, the sum of $15,050.62; and the amount of facilities furnished other than money (excepting some small articles of which no account has been received) is in value $2,353.50. Since the date above referred to, no payment has been made by the department on that account.

I have reason to believe that Mr. Colt did communicate to the Hon. A. P. Upshur information as to the combustible agent employed by him in his experiments, while that gentleman was the head of this department; that this communication was made under an injunction of secrecy; and there is nothing in existence in this department to show, so far as I am informed, that the secret has been divulged by him, or is applicable to the purposes of the government, without some arrangement with Mr. Colt, which this department has no authority to make.

As Mr. Colt's experiments were, in effect, closed about the time I entered on the duties of this office, I have declined to receive a communication of Mr. Colt's secret, of which the knowledge could only be useful in determining on the effect of experiments which had already been made, which I had not witnessed, and which there was no means at the disposal of the department to have repeated.

I have the honor to be, very respectfully, your obedient servant,

J. Y. MASON.

No. 5.

WASHINGTON CITY,
Fuller's hotel, May 9, 1844.

SIR: If consistent with your sense of propriety, I should like an opportunity of seeing a copy of the report you must make on the subject of my

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submarine battery, in compliance with the resolution of the House of Representatives, previous to transmitting it to that body.

My object in making this request, is to be able to make to you suggestions for your consideration, if any strike me as important, in regard to the existing relations between the United States government and myself.

I will call at your department at any time you may direct.

SAMUEL COLT.

Hon. Wm. WILKINS,

Secretary of War.

Memorandum.—To the above, a verbal refusal was given to S. C.

No. 6.

ENGINEER DEPARTMENT,

Washington, May 1, 1844.

SIR: The resolution of Congress of the 19th ult., having been referred by you for report to this office, I have the honor to submit thereon the following remarks. The resolution is in the following words:

"Resolved, That the Secretaries of War and Navy be requested to communicate to this House the fact, whether the combustible agent used by Mr. Colt was a secret before he made the same known at the seat of government; and whether the mode of its application to harbor defence be new; and if new, what objections there are against its adoption, if objections do exist."

I. Whether the combustible agent used by Mr. Colt was a secret before he made the same known at the seat of government?

I understand this inquiry to refer to the combustible agent, by which fire is conveyed to deposits of gunpowder, and not to the gunpowder itself, nor to any substance substituted for gunpowder; and this agent I understand to be galvanism, or voltaic electricity. As to the nature of this agent, there is, I suppose, no concealment. The details of Mr. Colt's mode of conveying the power of the galvanic battery to distant charges of gunpowder have not been communicated; he has stated to me, in conversation, that this is a secret between himself and the Navy Department.

The process thus concealed from common view, may be new partly—perhaps entirely; but, however that may be, there is no doubt that the idea of making this use of galvanism did not originate with Mr. Colt; and that its successful application to submarine explosions was made by others, before Mr. Colt's projects were submitted to the public.

The use under water, of gunpowder, in blasting rocks, levelling for foundations, removing obstructions to navigation, and even blowing up vessels, is a matter of common notoriety amongst persons conversant in such operations. But, until within a few years, fire was communicated in such cases, by matches or fuses of different kinds, through water-tight tubes, &c.; all of which means seem applicable only to charges that are near at hand.

In 1831, however, an eminent American chemist, (Dr. Hare, of Philadelphia,) at the close of a paper describing a process by which he had exploded a number of charges of gunpowder by the use of a galvanic battery, says, "it must be obvious, that, in all cases of blasting under water, the plan of the tin tube, and ignition by a galvanic circuit, must be very eligi-

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ble." Although the English have since had much more experience than we in carrying out this idea, they acknowledge this to be the first suggestion of the voltaic process. Since this announcement by Dr. Hare, originality in this matter must be restricted to the details, which admit, no doubt, of considerable variety.

Col. Pasley, of the English corps of engineers, after much experience in submarine explosions by the employment of fuses, matches, &c., began experiments in the autumn of 1838 with the voltaic battery; and, in the spring of 1839, succeeded in firing several charges in deep water, at the distance of about 500 feet.

In the same year, Mr. Roberts, near Edinburgh, used a voltaic battery in firing charges under water.

In July, 1839, Col. Pasley caused experiments to be made as to the effects of an increased size in the conducting wire, and augmented power in the battery in exploding more remote deposits of powder, in which he extended the distance to 1,950 feet—a limit set, not by want of power in the apparatus, nor by defect in the arrangements, but by the length of wire with which he was provided. There was nothing in the experiments then made, nor is there anything in those made since, affording any reason to doubt that, had his provision of wire been adequate, he might, at that time, have extended his command over a length of wire as great as has ever been employed.

"As soon as Col. Pasley" (to use the language of a semi-official report of these proceedings, dated in 1840) "was satisfied that he could depend upon the voltaic battery at any depth of water, and in any current however strong," he made arrangements for blowing to pieces the wreck of the line-of-battle ship Royal George, sunk at Spithead in 1782, and then lying embedded in mud at a depth of about fourteen fathoms; which operation was pursued through several seasons. Numerous embarrassments connected with the position of the wreck in deep water, in a strong tide way, and often a rough and heavy sea, attended the early operations; but they were all overcome, and the process reduced to a system simple, easy, and certain.

In December, 1839, the wreck of the barque Equitable, of 420 tons, was blown up in 30 feet water in the river Hoogly, in India—also by voltaic electricity.

In the year 1840, Mr. Alexander Paris, an able American civil engineer, who was engaged, under the general government, in the construction of quay walls and launching ways at the navy-yard in Portsmouth, N. H., had recourse, with perfect success, to the same agent in levelling the rocky bottom to receive his walls, in depths varying from 25 to 30 feet at high water. He preferred, for his galvanic battery, Dr. Hare's calorimeter.

With this experience, (which we see has been acquired by others than Mr. Colt,) with much more of similar nature to which I have not adhered, and a vast deal more, no doubt, of which I have no information; for, in the development of this branch of chemical philosophy, great improvements are daily made in the details, in sources of power, in modes and purposes of application,—with this knowledge, any intelligent person could, and by merely applying means which have been gratuitously contributed not say that he would use the same means identically, because the same effects may be reached by processes varying in particulars; but he would

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accomplish the same end with equal certainty, although what Mr. Colt claims as the secret of his process should never transpire.

I should consider myself as risking nothing were I to engage to have these results repeated, without the least reference to Mr. Colt's—using only processes that are now the property of the scientific world—with modifications probably, but with such only as ingenuity, by no means rare, could supply.

Even within the short time that has elapsed since Col. Pasley and Mr. Paris's experiments, and others above adverted to, the galvanic battery has been greatly extended in its power and convenience of application; but by means openly announced to the public, and better than which Mr. Colt need not have used in his late exhibitions.

To meet the probability of, its being said that, after all, the agent is not galvanism,—I have to add, that galvanism will, at any rate, produce identical effects. If it be further said, that the explosions are not the work of gunpowder,—it is only necessary to add, that pyrotechnical displays not less striking, may, nevertheless, be the work of that material.

## II. Whether the mode of the application of this agent to harbor defence be new?

I am not aware of any project antecedent to Mr. Colt's, for communicating fire by galvanic electricity to deposits of powder placed in channels and harbors, for their defence. If, however, it were once thought advisable to make these deposits, it would seem that this mode of igniting them—a mode which has been shown to have been of frequent use in causing explosions under water for other purposes—would very naturally have been taken into consideration; but, I must say, I am not aware of any such project.

If the purport of the resolution is (without confining its meaning to the mere process of ignition) to inquire whether the idea of defending harbors by such deposits of gunpowder placed in the track of vessels is new, then the answer is in the negative; Fulton's projects of this sort are more than 40 years old. Among his various devices for producing submarine explosions, and for attaching torpedos, as he called them, to the bottom of vessels, was one (perhaps the best of all such inventions) for anchoring one or more lines of torpedoes across the channel, and below the surface of the water, and in such proximity to each other that vessels could not pass without striking one or more. Each of these magazines of powder was to be so fitted on the outside, that the pressure of passing bodies would set free an internal lock, like a gun-lock, thereby giving fire to the enclosed gunpowder. This invention, the details of which afford scope for much variety, seems to me more likely to be usefully applied to purposes of defence, and much freer from objections, than any kindred project. The idea has long been before the world, to be availed of, possibly, in particular localities, in addition to other well-tried means, when suitable occasions shall present themselves.

With Mr. Fulton's other device of detached torpedos, that were to be drifted down upon anchored vessels—although, in his preliminary experiments in the harbor of New York, he had completely demolished the vessel submitted to his power—one or two actual attacks that were attempted during the last war, produced no other effect than causing a more than usual vigilance in the blockading vessels. This particular invention of drifting torpedoes, notwithstanding the striking success of the experiment

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in the presence of thousands of spectators, never partook of the public confidence, and received little further aid from the government.

These notices but repeat the well-known fact, that submarine explosions are not new resorts as measures of defence, in the minds of ingenious men; however it may be with Mr. Colt's means of causing the explosion.

## III. If new, what objections there are against its adoption, if objections do exist?

Means as applicable to the great object of national defence may be local or particular, or they may be general. Of the former class, it would be difficult to mention any means that can be brought to inflict bodily hurt upon man, or injury upon the works of his hands, that may not find some useful application in war.

We pride ourselves in these days (and not without reason) upon the highly advanced state of military science; upon the great exactitude to which its combinations lead; the precision of its results, whether in respect to masses or individuals; upon the perfection of its machinery and its arms; and yet, indispensable as this advanced condition is, in order that one nation may be in equilibrium with another, or may be able promptly to put herself upon the same level, there would be hardly a day of active campaign in which advantageous recourse would not be had to some of the simple practices of early warfare. The bayonet is not, however, likely to be set aside, because in a *mêlée*, the fist may be sometimes used with effect even now; nor the musket, because in certain positions the arrow may be the preferable missile. But, while particular circumstances of this nature do undoubtedly sometimes arise, no judicious person would therefore decry the great improvements that have grown out of the experience of war, or aim to supersede any of these by devices not approved by an equally severe test. Military experience has enacted, as an inflexible law, that no device, however plausible, shall be admitted to confidence as a military resource, except as it shall make its way by success in actual war, or in a long and severe course of experience analogous thereto. The success of any device as a local or particular means, ought, in this way, to be thoroughly established, before it can enter its claim as of general utility. And the reason for this is plain: as the means in actual use are the fruits of this kind of experience, they should give way only to means that have been proved superior, by a trial not less thorough.

These observations seem properly to precede the remark that the project of defending harbors by deposits of gunpowder arranged for blowing up the passing vessels of an enemy, is very far from possessing the sanctions which alone could warrant a reliance upon it, to the exclusion of a single one of the means of known efficiency.

Still, it might be conceded that, in certain positions, and under particular circumstances, a partial resort to it might be advantageous. I can imagine a case that would call for the use of Perkins's steam-gun—an invention which excited the public wonder a few years ago—in preference to any other arm; and I can also conceive circumstances that would justify the trial of this project. But even were any such case to present itself, the object could be accomplished without recourse to any secret means—to any process not the common property of the world. I must add, however, that even in instances that would seem to admit this latter trial, any arrangement founded

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on the principle of Mr. Fulton's anchored torpedoes, presents itself much
more favorably to my mind.

To apply this project as of general use, or as a sole resort, would, it seems
to me, be as utterly in vain as it would be unwise. In order to explode
these gunpowder deposes opportunely, it is, of course, necessary that the
agent shall know, with exactness, when the passing vessel is over the charge
—very little latitude being allowable. Now, the only mode of judging is
by the eye; there is no time for computation, nor even for comparison of
opinions; and to say that a man can guess within several hundred feet, is
to give more accurate vision than the most experienced eye would claim.
In proof of this, it is only necessary to compare the opinions of bystanders
as to the distance of any remote object, whether passing by land or water.
In order that there may be any approach to accuracy in this respect, it is
necessary, moreover, that the agent shall be placed in, or near, the line in
which his magazines lie; if not, he can no better decide when the enemy
is crossing this line, than he can tell the particular point of the line over
which he passes. But if there be, unavoidably, this uncertainty by day-
light, how will it be at night, when the outline of the vessel can only be
dimly made out, if seen at all? How is this resort then to be applied?

Passing from this point, as to which many sources of uncertainty are
obvious, we will suppose an enemy to hesitate, notwithstanding, as to run-
ning the hazard of the passage—preferring to land a force, and break up
the arrangement for communicating fire to the charges of powder. The suc-
cess of this landing can be prevented in one of two ways only. There
must be a fortification and garrison capable of resisting the enterprise—
which we know, from the lessons of history, will be composed of a force
commensurate with the importance of the object to be gained; or, there
must be encamped upon the spot an army capable of defeating it without
the aid of fortifications. The defence rests, then, either upon the fort or
upon the army, and not upon the deposes of powder; for, if this protect-
ing force be overcome, there will then remain nothing to prevent the break-
ing up and destruction of the galvanic arrangements. Or the enemy may
prefer to destroy the system of conducting wires as they lie upon the bot-
tom. For this purpose, he may send at night his heavy boats—aided, per-
haps, by one or two small steamboats, each provided with the means of
dragging the bottom, so as to break the wires, and tear away the powder
cases. Traversing the channel in all directions within the scope of the
deposites, a single night would suffice to clear away from the portion of the
channel designed to be followed, every trace of submarine communication.
Nor would the use of hawsers, or even chains, intended to secure the wires
from the dredges, avail; because, with means supplied by the larger boats
of men of-war, these could be lifted and cut off.

On the supposition that this is to be the main dependence for defence,
there would, however, be no necessity for hurry in this dredging operation;
the enemy might take his own time to it. Bringing his vessels of war into
convenient proximity, he could delay his passage until a deliberate exami-
nation had shown that not a clew remained unbroken.

It must not be urged that danger to the boats will prevent the scouring
of the bottom; because, to say nothing of the uncertainty which must ex-
ist on shore as to the exact positions of the boats at any moment in the
night, we know that greater hazards are encountered in war with alacrity.
A little additional pay to the soldier, and the thirst for distinction in the

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officer, keep the military miners stimulated for weeks, during a siege, to will-
ing and ardent labors, in the midst of almost hourly explosions.

Nor must it be assumed that the positions occupied by these means of
defence will be unknown to an enemy. If these were not settled by the
features of the harbor, money would procure this, as it does all other mili-
tary information. If the dark and complicated countermine galleries of a
fortification cannot remain unknown, we need not look for the concealment
of that which must be executed in the face of the public.

I could enlarge on these and other considerations of a like nature, ex-
plaining counter-devices, by which the project, standing by itself, would be
rendered nugatory; but such cannot be necessary, and I will sum up my
remarks in the following words:

That the project of Mr. Colt, as a sole means of defence, is wholly un-
deserving of consideration; as an auxiliary, although it might in some sit-
uations be resorted to, it should in all, or nearly all such cases, be regarded
as inferior to means that have long been known; and, even when resorted
to, that it may be applied without any indebtedness to Mr. Colt, either as an
inventor, an improver, or an applier of the process.

Mr. Colt declines affording you the explanations and information respect-
ing his process, which you invited him to communicate. This circum-
stance does not, however, affect the tenor of this report. As before observed,
although we should forever remain ignorant of the mode of operation pre-
ferred by him, the results he has given to the public can be repeated by
others whenever they may be called for.

I have the honor to be, very respectfully, your most obedient,

JOS. G. TOTTEN,
Colonel and Chief Engineer.

No. 7.

WAR DEPARTMENT, April 29, 1844.

SIR: I have the honor to enclose you a copy of a resolution adopted by
the House of Representatives, in relation to "the combustible agent used
by Mr. Colt;" and beg you will pardon me for asking your attention to the
first branch of the resolution.

It is understood that the explosive agent used by Mr. Colt is gunpowder;
and that this is fired by means of galvanism, or other similar agency.

Your pursuits having led you, doubtless, to an acquaintance with what
has been heretofore done in this branch of practical science, the War De-
partment would be much obliged by the communication of your views in
reference to the claims which Mr. Colt's methods may have to originality.

My object is not to impose labor or detail upon you. Your opinion, trans-
mitted to me with as much brevity as you may think proper to use, and
with as little delay as may suit your convenience, will be thankfully re-
ceived as a contribution in the advancement of a public inquiry.

Very respectfully, &c.,

WILLIAM WILKINS.

Professor JOSEPH HENRY,
Princeton, New Jersey.

[A similar letter was addressed to Professor Hare, of Philadelphia.]

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Doc. No. 127.

PHILADELPHIA, May 1, 1844.

SIR: 1. In reply to your letter of yesterday, and to the requisition made by the House of Representatives of the United States, I hasten to say, that, as respects the employment of a galvanic current to ignite a wire, and by means thereof to explode gunpowder, whether for the purpose of rock-blasting, or for warlike defence or annoyance, the galvanic process employed by Mr. Colt has not the slightest claims to originality. This will be made evident by an inspection of the 12th volume, page 221, of the Journal of the Franklin Institute, of which there is no doubt a copy in the national library in the Capitol. It will therein appear that I published an account of the simultaneous explosion of twelve charges of gunpowder, at the distance of one hundred and fifty feet, by one battery. I performed the experiment at that distance, to show that the apparatus might be remote from the cavity in which ignition is to be effected by it; but it was perfectly well known to myself, and all others acquainted with galvanism, that many miles might intervene, the number and size of the galvanic series being proportionally enlarged.

2. The process thus described did not differ from one of which I published an account in volume 2, page 315, Silliman's Journal, in 1820, as the means of igniting gaseous mixtures in my eudiometrical apparatus. The rock blasting was suggested by the application to me for assistance of a projector of the name of Shaw, who had attempted, with little success, to employ electricity produced by friction for that purpose, with occasional and uncertain success, and wished to learn by what means he could avoid the disappointment resulting from the paralyzing influence of moisture.

3. It may be observed that paragraph the 4th, on page 223 of the 12th volume of the Journal of the Franklin Institute, before mentioned, consists of the following words: "It must be obvious, that in all cases of blasting under water, the plan of a tin tube, and ignition by a galvanic circuit, must be very eligible." The concluding paragraph of the communication (page 226) is as follows: "It can scarcely be necessary to point out that the method of communicating ignition described here for the purpose of rock-blasting, may be applied as the means of exploding a mine. As, for instance, the mines associated with the fortifications erecting near Newport, as a part of the means of annoyance, might have a communication through copper wires, with a galvanic apparatus, in those situations to which theбы- sieged might be expected to retire; putting it thus completely in the power of the commanding officer to select that time for the explosion when its effects would be most serviceable."

4. Thus it appears that I had represented my process as peculiarly applicable to blasting under water, and exploding mines as a means of military annoyance. Moreover, it will appear from the Journal of the Franklin Institute, (vol. 1, 3d series, for 1841, page 154,) that the process devised by me was used in 1840 by Alexander Paris, civil engineer, who mentions the previous employment of it in England for removing the wreck of the Royal George, and in several other successful enterprises.

5. Professor O'Shaughnessy, of Calcutta, informed me, when in this city last spring, that he had (in consequence of reading of my experiments) undertaken with complete success, by a similar process, to remove from the channel of the river Hoogly the hull of a large sunken vessel which interfered with the navigation.

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6. Professor Draper of New York, has informed me that he instructed Mr. Colt as to the process which he uses; it being understood by him at the time that it was one which I had previously employed.

7. I am ready to admit that Mr. Colt must have been judicious and skillful in availing himself of the means which he has owed to the invention of others. As respects the employment of the process as a means of harbor defence, the only objection that occurs to my mind arises from the great difficulty of conceiving how it can be applied so as to avail against movable bodies like ships of war. If Mr. Colt can so employ an exploding apparatus as to defend a harbor, I can see no objection to the project, excepting that it must be very precarious. Any number of casks of gunpowder may be made to float in a channel, and may be exploded by the means which I have devised, at any desirable instant, either successively, or all at once. Where the channel is so narrow that an approaching vessel could not pass without coming very near one or more of them, evidently she might be discomfited. The casks might contain rockets and fire-balls, which might fly to a great distance, and set fire to the sails of shipping. But where there is a squadron of ships, the casks being so exploded as to injure the first, there would be no means of preventing the passage of the remainder.

8. It occurs to me to suggest that a floating battery might be so placed as to have the guns discharged at any moment, in a way to destroy a passing ship.

9. Of the peculiar mode in which Mr. Colt proposes to employ galvanic ignition in harbor defence I have no knowledge; and of course, on that subject, I cannot form any opinion.

10. The fact that my apparatus, in the hands of my ingenious countryman, Paris, was found superior for blasting under water to that employed by Colonel Pasley, proves the folly of the reason assigned by him for his not employing it—that it had not been used under water. (See Franklin Journal.) But, as the distinguishing feature of my process consists in the use of the galvanic circuit, it makes but little difference whether the one or the other form of the galvanic battery were employed.

11. While the process of blasting by galvanism is before Congress, I beg leave to call their attention to the humane object for which it was devised. In England, any effort of this kind is cried up both as an individual and national honor. Look at the instance of Davy's safety-lamp. The neglect of the use of my process for rock-blasting has caused many persons to be killed or crippled. I presume, however, that the resolution of Congress, in consequence of which I am honored by your letter, is not sufficiently broad to make it proper to take into view any other object besides harbor defence.

12. Since the preceding pages were written, I have found in the United Service Journal, published at London, an account of the operations of Col. Pasley in removing the wrecks of several vessels, especially that of the Royal George. It appears that, after bungling for some time with other means of communicating ignition, Colonel Pasley became acquainted with my process for effecting that result, and therefore resorted to the galvanic circuit for the purpose alluded to. (See vol. 1, 3d series, Franklin Journal, already referred to, page 158.) With true British pride, however, they determined to go through a vast deal of trouble to get up a plan of their own,

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when the experiments of Paris show that my plan, already perfected, was preferable to that to which they resorted.

I subjoin extracts A and B from the work above mentioned.

I am, sir, your obedient servant,

ROBERT HARE.

WILLIAM WILKINS, esq.

A.

Extract from the United Service Journal and Naval and Military Magazine for 1839, part 2d, pages 187, 188.

> "It is well known that gunpowder had often been fired by the common electrical machine in a lecture room or scientific institution; and Mr. William Snow Harris, in the course of his very able and important researches respecting the expediency of securing ships against the effects of thunderstorms, by lightning-conductors, did wonders in this way by a common electrical machine placed in the cabin on board ship, with which he fired gunpowder at a considerable distance, by wires passing through water before they reached the charge that was to be exploded, and which, if we are rightly informed, were also previously passed through a barrel of gunpowder, which was not injured by them; the object of which experiment was to prove that the electrical fluid, received by a conductor fitted on his principle from the mast head of a man-of-war, might be dispersed in the water beneath, without injury to the vessel, even if the conducting-wire should be led through the powder magazine. Mr. William Snow Harris's experiments, which astonished a number of distinguished naval officers and other spectators at Plymouth, in the year 1823, were described in the 'British Press' of the 17th, and in the 'New Times' of the 25th of March of that year; notwithstanding which, the circumstance of the electrical machine requiring warm dry air to render it effectual, opposed a strong objection to the adoption of it for the practice of mining; besides which, no common military or civil miners could be expected to acquire the same expertise in the manipulations of this delicate machine which was displayed on that remarkable occasion by this justly celebrated electrician. In fact, a Mr. Moses Shaw afterwards adopted the electrical machine for blasting rocks for the purposes of building, and even took out a patent for it in America; but finding that it would not answer, excepting in very warm dry weather, and that consequently it was inefficient for a great part of the year, he consulted Dr. Hare of Philadelphia on the subject, who recommended the voltaic battery in preference, which he himself had long used to ignite explosive gaseous mixtures, and who brought the use of it for blasting in rock to considerable perfection; for he states that he has fired twelve blasts simultaneously, at the distance of 130 feet, by a powerful voltaic battery of a peculiar construction, which he calls a deflagrator, or calorimeter. Thus, though it is probable that the voltaic battery may have been used many years before for firing small charges of gunpowder, by way of experiment or of curiosity in a lecture room, Dr. Hare has the merit of being the first to apply it to a useful practical purpose. His arrangements, previously published in Silliman's American Journal of Science, were de-

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scribed in a paper communicated by him to the British association at Bristol, in 1836, the substance of which appears in vol. 5, as part of the transactions of the sections for that year, (see page 49.) In preparing his simultaneous explosions, he does not make a circuit from one pole of the battery to all the charges in succession, and from the last of these round again to the other pole; but he uses a complete pair of conducting-wires each charge, the ends of which he solders together in two parcels, each connecting one half of the wires, and the other the other half, and so arranged that no two wires belonging to the same charge are brought into the same parcel. One half of his wires only are copper, the others of iron; the latter not being in one single wire, but composed of three small iron wires combined together, by twisting them like the strands of a rope. In preparing his charges, he uses tin cylinders to be let into the holes in the stock. The end of the copper-wire is soldered to the upper side of each cylinder, whilst the end of the iron wire passes from the bottom of the cylinder, to which it is soldered, through a cork at top. In the centre of the charge two of the twisted iron wires are cut through, leaving only one strand, as it may be termed, which is much finer than the others, and which, to prevent breaking, is enclosed in a small hollow piece of dogwood, having some fulminating powder in it, as being more inflammable than common gunpowder. When a number of charges are to be fired, the ends of the two parcels of wires, soldered together as above described, are also soldered one to one pole, and the other to the other pole of the battery; but this sort of connexion does not yet put the battery in action. This is lone in an ingenious manner, by the movement of a lever, which, by completing the voltaic circuit, causes the fine piece of iron wire in the centre of each charge to become red hot, and thereby the whole are ignited."

B.

Extract from the United Service Journal and Naval and Military Magazine, for the year 1840, part 1st, pages 160 and 161.

> "Lieutenant Symonds, after having personally superintended the lowering of the charge and the removal of this lump, went to No. 1, and took post by the voltaic battery which had been placed there, in readiness to fire the charge. The colonel then ordered the bugler, who attended upon him in No. 5, to sound the PREPARATIVE, and in a few minutes afterwards the FIRE; and while the last note of the second bugle-sound was still audible, a smart shock, like that of an earthquake, was felt; and a report, like that of a heavy gun at a moderate distance, was heard; and, in a few seconds afterwards, a great column of water, beautifully sparkling in the sun, was thrown up to the height of thirty or forty feet, in the form of a bee-hive nearly, the appearance of which was welcomed by the hearty cheers of the spectators. After this brilliant jet of water had fallen down, a circular wave, of which the surface was discolored by mud from the bottom, was observed gradually extending itself to perhaps a hundred yards in diameter, nearly in the centre of which the wood work of the cylinder, broken into small pieces, all lighter than water, came floating up to the surface, and

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gave rise to an amusing scramble of persons in boats, rowing to the shore with all haste to seize upon those fragments, which they eagerly carried off as relics of the Royal George. The shock of this explosion was sensible felt at Portsmouth, by persons sitting in their houses, and not expecting thinking of it at the time."

No. S.

PRINCETON COLLEGE, N. J., May 3, 1844.

SIR: I have the honor to acknowledge the receipt of a letter from the War Department, requesting my views as to the originality of Mr. Colt's method of producing explosions; it being understood, according to your statement, that the combustible he employs is gunpowder, and that this is fired by means of galvanism, or other similar agency. In answer to this letter, I respectfully submit the following:

The explosion of gunpowder at a distance, by means of galvanism, has been familiar to men of science and practical engineers for several years. The method now generally used was made public in 1832, and is the invention of Dr. Hare, of Philadelphia. It consists, essentially, in extending between the reservoir of powder and the operator two long thick wires, one by a short wire of platinum of small diameter. The other ends of the copper wires, in the hands of the operator, at the desired moment of explosion being suddenly brought in contact with the two poles of a galvanic battery, a current of galvanism is transmitted through the circuit of wires which, heating to redness the piece of platinum in the midst of the powder, produces the explosion.

The practicability of exploding gunpowder at a distance, in this way was established by the experiments of Dr. Hare; and his results were verified and applied to actual practice by several persons, before the time of the exhibitions of Mr. Colt. In 1839, a series of experiments by Colone Pasley, of the royal engineers, was published in England, relative to the explosion of a large quantity of powder by the galvanic process, at the bottom of the river Medway; and, as an evidence of the wide diffusion of the knowledge of this process, I may mention, that I have now before me a book published in Calcutta, in 1841, in which is given a minute account of the experiments of Dr. O'Shaughnessy, of the Bengal army, in destroying a wreck sunk in Hoogly river, by a method which the author himself calls the process of Dr. Hare.

The experiments on the Hoogly, as well as those on the Medway, were made in 1839; and since that time, as it would appear by the various publications on the subject in the different English scientific journals, the application of the galvanic process of exploding gunpowder has become general. In 1841, I established part of the business of the English engineer. In short, I considered the laws of the transmission of electricity through long wires as fully developed by the researches of Ohm, Wheatstone, Daniell, and others, at least as far as they are applicable to the process in question; that I do not think it in the least degree probable that Mr. Colt has added a single essential fact to the previously existing stock of knowledge on this subject.

In conclusion, I wish it to be distinctly understood that the foregoing

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remarks are all made in reference to the method of exploding gunpowder at a distance by means of galvanism, and are intended as a specific answer to the question proposed to me in your letter. Mr. Colt may, perhaps, not attempt to found his claims to originality on the invention of the galvanic process, to which he can have no title, but on a new application of this process to a method of harbor defence; and also on a new arrangement of this subaqueous magazines for the same purpose. Of the validity of claims thus founded, I am not called on to give my opinion; but, in justice to Mr. Colt, I ought to say, that whatever may be the result of the investigations relative to the originality of his plans, I think he deserves credit for the industry and practical skill with which he has brought them before the public.

JOSEPH HENRY.

Hon. Wm. WILKINS,

Secretary of War.

No. 9.

WASHINGTON, May 7, 1844.

SIR: I have carefully perused the communication from Professor Hare, which you placed in my hands, and do not think it necessary to add anything to the remarks of that gentleman. The view he takes of the subject to which it relates, is precisely that which had presented itself to my mind; and the authorities which he has adduced, being principally found on the pages of my journal, are such as I should have immediately resorted to. Dr. Hare has done me the honor of referring you to me, should you desire any information in addition to that which his communication affords. I cannot pretend, by anything I can say, to add weight to his statements; but he is aware that I am perfectly [acquainted] with his agency in perfecting the plan for effecting the explosion of powder in blasting rocks, and for other purposes, by the means of galvanic electricity; which plan, slightly modified, is that which has been successfully adopted.

Mr. Colt may have made some new modification of the conducting wires, or in some other parts of the apparatus used by him; but this is a question of little importance, as every person well acquainted with chemistry and mechanical philosophy, and who is apt at manipulation, could very readily accomplish all that has been effected by that gentleman, and without liability to failure. There are hundreds of men of science in our country, who would unhesitatingly engage so to do. Without consulting with those gentlemen, I may, with confidence, refer you to Professors B. F. Morse, A. D. Bache, C. G. Page, and W. R. Johnson, now in this city, as I am certain that they will unite in confirming these statements.

I am, sir, very respectfully, your obedient servant,

THOS. P. JONES.

Hon. Wm. WILKINS,

Secretary of War.

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