Court Opinion

ID: 8804426
Source: CourtListenerOpinion
Date Created: 2022-11-26 14:43:13.984242+00
Date Added: 2024-06-11T17:04:02.210260
License: Public Domain

BUFFINGTON, Circuit Judge
(dissenting). Putting aside all minor incidents, this case in my judgment, involves one broad, basic and far-reaching question, and that is whether any and all advance and improvement in the sphere of air flotation in mineral recovery for the. next few years shall be subjected to what will practically be a blanket claim for any use of air as a flotation agency.
The claim which we are asked to construe and apply is for:
“The 7i6)-ei»-clescribad process oí concentrating ores, which consists in mixing the powdered ore with water, adding a small proportion of an oily liquid having a preferential affinity for metalliferous matter ("amounting to a l'ractioia of one per cent, on the ore), agitating the mixture until the oil-eoatéd mineral matter forms into a froth, and separating the froth from the remainder by Potation.”
I say, putting aside all minor incidents, for it is perfectly clear that if all kinds of air flotation and all kinds and degrees of agitation are covered by this claim, the infringement of the defendants is self-evident by their use of compressed air which produces some agitation and causes air flotation. To my mind, and for reasons I shall now discuss this claim should not be awarded this sweeping scope which will paralyze the subsequent development of a great art.
Now, if any broad right to monopolize all air flotation with a limited use of oil but an unlimited use of agitation exists, it arises by virtue of a contract made between these patentees and the government; and that contract is embodied in the claim of the patentees, made by them and conceded by the government, the other of the contracting parties. *776and the consideration for that claim is the required statutory disclosure made by the patentees—
“ * * * of the manner and process of making, constructing, compounding, and using it, in such full, clear, concise and exact terms as to enable any person skilled in. the art. * * * to make, construct, compound, and use the same, * * * and he shall particularly point out and distinctly claim the part, improvement, or combination which he claim's as his invention or discovery.”
Turning now to the patent itself, which has been held valid and described by the Supreme Court as “patentable, as new and original as it has been found useful and economical,” let us inquire, first, what was tire new thing disclosed, for therein we have the consideration for the claim; and, second, what claim was allowed in consideration of such disclosure. This line of approach is to my mind imperative, first, because while an invention may be broader than a claim, a claim can never be broader than an invention. Finding from this claim that it concerns two things, oil and agitation, we must necessarily turn to the specification and there ascertain what was the new disclosure as to oil and agitation. In substance, it' was the disclosure of a process in which a hitherto unused minimum of oil and a hitherto unused maximum of agitation were used. Each of these disclosures was summed up by the Supreme Court in these words:
“The process of the patent' in suit, as described and practiced, consists in the use of an amount of oil which is ‘critical,’ and minute as compared with the amount used in prior processes, ‘amounting to a fraction of one per cent, on the ore,’ and in so impregnating with air the mass of ore and water used by agitation — ‘by beating the air into the mass' — as to cause to rise to the surface of the mass, or pulp, a froth, peculiarly coherent and persistent in character, which is composed of air bubbles with only a trace of oil in them, which carry in mechanical suspension a very high percentage of the metal and metalliferous particles of ore which were contained in the mass of crushed ore subjected to treatment. This froth can he removed and the metal recovered by processes with which the patent is not concerned.”
It will thus be seen that, first, the quantity-iof oil; secondly, the character of agitation; and, thirdly, the resultant froth — constituted the disclosure. Apart from the authoritative statement of the Supreme Court as to what was the invention of these patentees, which of course controls us, it is clear, both from the proofs, the physical facts, and a general knowledge of the art, that such was the case, and that this discovery is bottomed on agitation — the new kind of agitation disclosed: — which made possible new extension of well-known properties and capacities of oil into fields oil had not reached by any previous methods of agitation. And it follows, if agitation of maximum ■character is the dominating factor that made possible the use of a minimum of oil, that claims which specify the use of oil and of agitation must not be read in a way that ignores the new and disclosed •agitation, which was not only the only specific agitation, but the only generic agitation the patentees disclosed. For it is perfectly clear that, if the art of air flotation to-day had stopped where the disclosure of ■this specification left it, the only method of air flotation would be *777the agitation disclosed in the patent. The specification does not purport to disclose or to make use of any newly discovered property of oil. Let that fact be clearly understood. That oil had three qualities was well known prior to this patent— -first, that oil had an affinity for metal particles; secondly, that the oil covering the. metal was of infinitesimal thinness; and, third, that oil has no affinity .for and will not coat gangue. Such being the known action of oil, viz. its affinity and its capacity for thus thinly coating it, and for not coating gangue, it is manifest that whenever oil, gangue, and metal particles arc mixed only a minute quantity of oil was needed to coat and actually did coat the mineral particles. The larger quantities of oil used were not needed or used to coat, but to float, the minerals. These facts are proved by the testimony of Sulinan, hereafter quoted and . alluded to in the House of Lords opinion, referred to later as an agitation which “assists the process of minute quantities of oil reaching minute particles, of metal.” But. while the small quantity of oil used as a .metal covering was a fact, the significance of that fact was not recognized in the preceding practice, for the manifest reason that in such art there was no use of oil alone for metal-covering purposes, but it was used for the double purpose — first, of oil covering; and, second, oil flotation. When, therefore, the patentees disclosed a process in which the oil necessary for flotation was dispensed with, the requirement of a small amount of oil for purely coating purposes became at once apparent and assumed a new significance. This was referred to by the Supreme Court when, in distinguishing it from the prior art, it said:
“The small amount of oil used makes it clear that the lifting force which separates the metallic particles of the pulp from the other substances of it is not to be found principally in the buoyancy of the oil used, as was the ease in prior processes,” etc.
From these considerations it will be seen that oil required and used for covering or coating the mineral particles, was precisely the same in quantity and function in prior practice and the practice of this patent. But what did happen was that the violence and duration of the agitation brought more particles into contact with oil than when the agitation was less violent. What, then, was the disclosure? This is clearly shown by the patentees in their specifications, where they show the nature of their improvement by contrast with the prior practices of the Cattermole patents. These proofs show that the present discovery was made while working on the process disclosed by Catlcr-mole and the specification recites its relation to Cattermole. Turning, therefore, for information to Cattermole’s patents, I find Caltermole’s process was one where oil was used for the double purpose, viz.: First, such small quantity as was necessary for metal particle covering; and, second, such large quantity as was necessary for metal particle flotation. I say “for metal particle flotation” advisedly, for, while the process finally ended, in the metal particles finding their way to the bottom and the gangue to the top, yet, as a necessary precedent step to making the metal particles go to the bottom, they were first floated upward, so as to enable them to there nucleate or agglomerate in such *778numbers that their combined weight overcame the buoyant capacity of the oil and they sank to the bottom of the vessel. These several! actions are set forth by Cattermole; as follows:
‘‘The invention depends upon the application of the following facts: First, when a mixture of powdered metalliferous matter and gangue is treated with oil suspended in water — that is to say, in emulsion — the oil has more or loss selective action and will coat the particles of metalliferous matter in preference to the particles of gangue, while the particles of gangue will be wetted by the water; second, if the water which is mixed with the oil is acidulated with mineral, fatty, or other acid the selective action of the oil will thereby be rendered more marked and decisive; third, if the proportion of oil is kept within reasonably low limits (differing in different cases, according to the nature of the mineral to be treated and the consistency and nature of the oil) and if the mixture of water, oil, metalliferous particles, and gangue be thoroughly agitated the metalliferous particles which have become coated with oil will adhere together and form granules, which granules, partly by reason bf gravity and partly on account of their bulk, as compared with the individual grains of gangue, will offer ready means for separation in an upcurrent separator, a jig, or other similar appliance.”
At tliis point it should be noted that as the patentees, in order to explain their disclosure, by reference make the Cattermole patent part of their specification, as the agitation used by the patentees was a step in the Cattermole process, and the Supreme Court found the paten-tees used and disclosed “an agitation greater than and different from that which had been resorted to before,” and also that “the extent of the agitation of the mass had been increased as the experiments proceeded until the series of the Gabbett mixers, fitted with the usual baffles, were speeded at from 1,000 to 1,100 revolutions per minute,” an inquiry into the character of the new kind of agitation used and disclosed by the patentees becomes essential to a due understanding of the disclosure made. As recognized and stated by the Supreme Court, this agitation consisted in the patentees speeding up a Gabbett mixer to 1,000 to 1,100 revolutions per minute. The extent of the agitation of the mass had been increased as the experiments proceeded until, as stated by that court, the “series of Gabbett mixers, fitted with the usual baffles, were speeded at from 1,000 to 1,100 revolutions per, minute.” It is apparent that this tremendous agitation speed through a mushy substance like pulp could only be reached by some special appliance impelled by powerful mechanism, since no ordinary paddle mechanism could stand the strain and furnish the power to meet such a requirement. We accordingly find that this was done by the pat-entees speeding up to hitherto unused speed, the device known and used in Cattermole’s process. Instead of seeking to move the whole pulp mass -by rotating paddle pressure on the whole mass — a thing which, owing to the length of the paddle required, would be impossible —Gabbett, as shown by his patent No. 444,345, segregated a part of the pulp. This segregated part alone he moved by paddles, and thereby set up a centrifugal force in the pulp in such segregated section, and thus made the centrifugally moving pulp itself the agency for moving the pulp on the outside of this inner dividing vessel. His device was built in two forms, one of which expelled the pulp at the top and the other at the bottom. Referring to the top expelling device, *779shown by Figure 1, which, as we shall hereafter see, these patentees necessarily declined to use, its operation is as follows: ■ ‘ •
“A is a conical shell, having internal ribs A2 and mounted on a shaft B, by which it ,is suspended within the vessel or tank G, containing the liquid to be acted upon, the shaft being carried at its upper end by a bracket I) and guided by a bush or stuffing-box Jil on the cover of the vessel G. Assuming this vessel to be charged with liquid to the level indicated and the shell A to be rotated by suitable gearing, such as Indicated at F, then the body of liquid within the shell being carried round with the same by moans of the ribs A' the centrifugal force will cause the liquid to rise along the inclined inner surface of the shell and to be ejected into the surrounding liquid when arriving at the upper edge thereof, while at the same time the pressure of the surrounding column of liquid in the vessel O will cause fresh quantities of liquid to enter the lower end of the shell A to make good the quantity discharged at the top. Thus a continuous circulation and consequent mixing of the liquid will be effected, as indicated by the arrows.”

That is, the machine discharged at the top. Its paddles being submerged in the segregated pulp, it could not beat in air. But neither Cattermole, nor the patentees, who adopted Cattermole, used the top outlet type of Gabbett’s device above described, but did use the other or top inlet type shown in Figure 9, although both moved the pulp in the same way, but in opposite directions. Selecting tlie top inlet or cone type shown in Figure 9 of Gabbett’s two forms, although both machines and agitators were, with the exception named, counterparts, there was a functional advantage in the top inlet type used which was vital to the working of the present patentees’ process.' And that there was a functional disadvantage in the top outlet type which would have been fatal to the working of their patent will, for reasons hereafter stated, be made clear. The only point now made is that the agitation, and the only agitation which the patentees disclosed as embodying the agitation of their process, was an agitation of one of two particular kinds, namely, one where they utilized their agitation power on a small zone of segregated pulp and where, for functional reasons, as we shall hereafter see, they applied such agitation to this segregated pulp as it was traveling in one direction; that is, downwardly. At this point we recall, as *780before stated, that Cattermole’s object was to nucleate or agglomerate into a mass, the individual, oil-coated mineral particles, or, as summarized by the Supreme Court, “agglomerating the oil-coated concentrate into granules heavier than water, so that they will sink to the bottom of the containing vessel.” As stated in the patent, “the more oil is used, the larger, softer, and less numerous the granules.” It was in the use and experimentation of this process that the discovery of the patent in suit was made, and these experiments were duly reported (see volúme 4, page 22 and following) from time to time. . From these reports it will be seen that the agitator used was of the cone-shape, upper-intake type already described and shown in Figure 9. By March, 1903, they found the value of both violent and protracted agitation, and that such protracted and violent agitation was effective to coat the mineral particles with oil:

*779

*780“Somewhat violent agitation is now required for a Jew minutes; the time being dependent upon the efficiency of the agitation, and varying from two to five or eight minutes, ■whereby the oil is released from the gangue and attaches itself exclusively to the mineral.”
Later, that is, in March, 1904, when a speed of 988 cone revolutions was reached and the effect of agitation effecting air-flotation was noted, where under the head of “Flotation Factor Used,” it was said:
“ * * * The coarse sands, when passing through the last two mixers, were allowed to be beaten well with air by keeping the liquor low in the mixers and using fast agitation, with baffles in. The concentrates were then found to be floated up in the outcast if only a general up current were used.”
The underscoring of the words “and” and “up” and the phrase “beaten well with air” and “fast agitation” show that the significance of violent agitation and the entraining of air was in the path of experimentation following the basic feature of the subsequent disclosure of the specification. In March, 1905, under the head “Influence of Peripheral Velocity of Cone” — and it must not be- overlooked that “cone” was the word which described the inlet top (Fig. 9) of tire Gabbett mixer — it was said:
“An increase in the peripheral velocity of the cone causes a decrease In the time required for granulation, a point being reached after which this decrease is slight.”
From this entry it vrtll be seen that increase of agitation was still regarded as and was the factor which was leading toward the discovery afterwards made and disclosed in the specification. In the next report both the speed and the type of Gabbett’s agitation is again emphasized by contrasting—
First. The low speed of the Gabbett as useless.
Second. The Gabbett cone mixer alone and with baffles added as an-additional, agitation agency.
Third. The inability of a centrifugal pump speeded higher than a Gabbett mixer to furnish the agitation requisite.
These points are all,outlined in said report as follows:
“The influence of the speed and type of agitation becomes a factor of great Importance to our recent experiments. Speeds of rotation (with a small Gabbett) varying from 3 to 500 revolutions per minute, proved almost useless.”
*781This shows the necessity of high speed agitation.
Continuing, the report said:
“We tlicn made a series of baffles which were placed in the Gabbett and which were ‘solid’; i. e., they occupied the greater free space of the Gabbett vessel from the glass sides up nearly to the working surface of the cone. They were found to be disadvantageous as they garó too violent agitation, and set up large eddy curi’ents in front of each baffle, greatly reducing rotation speed of the liquor in the Gabbett and adding water friction to such an extent to the rotating cone, that the power required to drive the latter was more than doubled. Oil replacing these solid baffles by the ordinary type of thin rod baffles, the granulation period was much improved, and the power consumed in driving the cone fell again to the normal.”
This, to. our minds, shows that, although the baffles increased the agitation, they precluded the kind or quantity of agitation desired. Manifestly the stoppage and delay of the pulp in eddies caused by the baffles stopped the steady and more frequent passage of the pulp through the cone, and this lessened the amount of agitation in the segregated zone where the air was beaten in.
Continuing, the report adds:
“We have also carried out a series of experiments with a small centrifugal pump in place of a Gabbett, to determine whether this gives a better form of agitation than the cone. * * * The following figures were obtained by Mr. lieochman yesterday in comparison with the Gabbett, find show the hitter to be distinctly preferable to the centrifugal pump experiments. We may say the centrifugal pump used was only a small one, having about a 4% to 5 inch chamber, but it was speeded up to about 1,200 revolutions per minute. 'The, pump therefore had a considerably higher peripheral speed than the Gabbett used in parallel tests.”
From this it will be seen that by a process of elimination it was becoming evident that the agitation desired was only obtainable on a cone or top outlet Gabbett mixer, and that the violent agitation by solid baffles and by the higher speed of a centrifugal pump were both objectionable.
In the light of subsequent events, it is quite evident why this was the case. In the first place, the top inlet or cone Gabbett mixer, by 1he rapidity of revolution formed a hollow air chamber around the shaft, into which air was drawn down and was there beaten by the paddles into and aerated the pulp. It is also clear that if solid baffles were used on the sides of the outer chamber, the rapid flow of the pulp would be measurably stopped and it could not pass as often through the cone, and therefore was not subjected to as much air beating as when the baffles were not used, as manifestly all thq air beating in took place in the cone. And lastly, while in the Gabbett mixer the revolving paddles in the cone were able to strike and beat the air into the surrounding pulp, it is evident the blades of the centrifugal pump, being necessarily wholly immersed in pulp, had no contact with air or an opportunity to beat air in. In other words, by its blade submerging, the centrifugal pump had no more power or opportunity to beat air into the blade-enveloping pump than would have been the case had the paddle blades of a Gabbett mixer with a top outlet (see Figure 1), whose blades would also be wholly immersed in the outflowing stream, been used.
*782It will-here be noted that as the centrifugal pump was the sole form of agitation used in this particular stage of the experiments, and, as it was discarded by the experimenters, that, tested by the acts of these patentees, no logical grounds existed for their counsel now planting themselves on the position that the pulp lift of a centrifugal pump is the air agitation of their disclosure and claim.
In the next report, Match 16th, under the head “Influence of the Percentage of Oil,” we find the effect of oil reduction is noted:
“The effect of diminishing the percentage of oleic acid is to alter the type of oiling; the higher percentages producing granules, and the lower froth. Six per cent, of the oleic acid on the mineral is sufficient to form good granules without much froth. * * * 0.62 per cent, oleic a*cid on the mineral is insufficient to form any granules, and nearly the whole of the mineral comes to the surface, on stopping the cone, as froth.”
It will thus be seen that it was agitation, and agitation of a selected type and speed, that gradually led up to the May 3, 1905, report, where the invention was definitely recorded. And when this was done it was accredited to the agitation indicated. That report says;
“We beg to hand you herewith a statement of the new method of oil concentration which we have been engaged in investigating and working out in detail, for the purpose of your forwarding to Mr. Courtney and his staff in Australia. It will be best to start with a short statement of the principle on which the process depends. In determining the lowest limit of oleic acid which could be employed in granulating, it was found that granulation, practically stopped at a range of about 0.5 per cent, of oleic acid on the mineral (60 mesh Broken Hill), in an acid circuit somewhat below 1 per cent, in strength. A certain amount of black mineral froth was, however, noticed as a result. On successively decreasing the amount of oleic acid below 0.5 per cent, it was found that, whereas granulation ceased, there was a growth in the amount of mineral float-froth under these conditions, and that the production of such float-froth appeared to reach a maximum when about 0.1 per cent, of oleic acid on mineral was used. This froth on collection was found to consist of oiled mineral slimes mechanically holding more or less coarse (oiled) mineral particles, the froth carrying between 70 to SO per cent, of the total mineral present in the charge. * * * The froth produced is not due to any action of the acid circuit upon traces of calcite present in the ore; i. e., not to the liberation of any gas in the charge by means of the dilute acid employed in the circuit. It has been located, on the contrary, to the air introduced by the Gabbett cone during agitation, the aw attaching itself to the oiled mineral slimes and to a large proportion of the coarse mineral particles, although both these materials can only be coated leith an infinitesimal amount of oil; i. e., oleic acid. That the formation of froth is due to air inclusions during the agitation, and not to carbonic acid or sulphuretted hydrogen is proved by the following experiences: * * * The plant consists of a series of Gabbett mixers fitted with the usual baffles, and speeded at from 1,000 to 1,100 revolutions per minute as regards the cone. These Gab-bett mixers are identical in every respect with those used for the original Cattermole process. * * * The operations are therefore summarized as follows: Gabbett agitation in the usual way with 0.1 per cent, oleic acid”
—thus themselves coupling with their invention at its birth the name of Gabbett and Gabbett agitation, which they now seek to avoid.
This terse and complete summary of the discovery in “Gabbett agitation in the usual way with 0.1 per cent, oleic acid” is also the summary of all that is set forth in the specification of the patent in suit, and further and other than “Gabbett agitation in the usual way with 0.1 per *783cent, oleic, acid” the long specification discloses no method or suggestion of other agitation, and gave none to the art. Such, specification starts with reference to the Cattermole patent, from which we have, quoted, Nos. 777,273 and 777,274, and states, that in the former:
“Oil varying from 4 per cent, to 6 per cent, of the weight of metalliferous metal present is agitated with an ore pulp so as to form granules which can be separated front the gangue. * * * We have found that if the proportion of oily substance is considerably reduced — say to a fraction of X per cent, on the ore — granulation ceases to take place, and after vigorous agitation there is a tendency for a part of the oil-coated metalliferous matter to rise to the surface of the pulp in the form oí a froth or scum.”
Such was the discovery the patentees embodied in the two claims here in issue, viz.:
Claim 1:
“The herein-described process of concentrating ores which consists in mixing the powdered ore with water, adding a small proportion of an oily liquid having a preferential affinity for metalliferous matter (amounting to a fraction of 1 per cent, on the ore), agitaimg Hie mixture until the oil-coated mineral latter forms into a froth, and separating the froth from the remainder by flotation”
And claim 12:
“The process of concentrating powdered ore which consists In separating the minerals from gangue by coating the minerals with oil in w'ater containing a fraction of one per cent, of oil on the ore, agitating the mixture to cause the oil-ooated mineral to form a froth, and separating the froth from the remainder of the mixture.”
It will he observed that these two claims do not themselves cover any complete, workable process of concentration disclosed in the specification, but are separate steps or elements in the process of workable concentration described in claim 3, which in addition to the above elements includes the elements of acid and heat. And that the extract quoted above, embodied in claims 1 and 12, was not a complete concentration process.but merely certain elements or steps of it, is made clear by the patentees, for, after reciting that “there is a tendency for a part of oil-coated metalliferous matter to rise to the surface of the pulp in the form of a froth or scum,” they add:
“This tendency is dependent on a number of factors. Thus the water in which the oiling is effected is preferably slightly acidified by adding say a. fraction of X per cent, np to X per cent of sulphuric acid or other mineral acid or acid salt, the effect of this acidity being to prevent gangue from being coated with oily substance, or, in other words, to render the selective action of the oil more marked. * * * Again, we have discovered that the tendency for the oily substance to disseminate through the pulp and the rapidity with which the metalliferous matter becomes coated is increased as the pulp is warmed.”
It will thus be seen that the workable concentration process which the patentees gave the art, was one in which the “flotation of mineral particles” was dependent on a number of factors, viz.: First, Gabbett agitation; secondly, 0.1 per cent, of oleic acid; thirdly, 0.1 per cent, sulphuric acid; and, fourth, heated pulp. And the workable process embodied all these four elements used in the method of working the invention, which the patentees necessarily showed in compliance with *784the statutory requirements that they “shall file in the Patent Office a written description of the same, and of the manner and process of * * * using i^ in Such * * * exact terms as to enable any person skilled in the art. * * * to use the same,” suggests that they regarded all four elements as constituting their workable process, and indeed they attribute to heat .the permeating and rapid coating of the minerals with oil.
Complying with the statutory requirement, the patentees say:
“Tie following is an example of tlie application of tiis invention to tie concentration of a particular ore. An ore containing ferruginous blonde, galena, and gangue consisting of quartz, riodonite, and garnet is finely powdered and mixed with water containing a fraction of 1 per cent, or up to 1 per cent, of a mineral acid or acid salt, conveniently sulphuric acid or mine or other waters containing ferric sulphate. To this is added a very small proportion of oleic acid (say from 0.02 per cent, to 0.5 per cent, on tie weight of ore). Tie mixture is warmed, say, to 30° to 40° centigrade, and is briskly agitated in a cone mixer or the like, as in the processes previously cited, for about two and one-half to ten nvinutes, until the oleic acid has been brought into efficient contact with all the mineral particles in the pulp. When agitation is stopped, a large proportion of the mineral present rises to the surface in the form of a froth or scum which has derived its power of flotation mainly from the inclusion of air bubbles introduced into the mass by the agitation, such, bubbles or air films adhering only to the mineral particles which, are coated with oleic acid.”
It is urged that this is but a sample method of showing how their process was workable. But the sample element consisted in the particular treatment given to a particular character of ore. It was not a sample of one of many possible kinds of agitation, for the kind of agitation applicable to all kinds of ore was concededly of one sort, namely, as therein stated, “briskly agitated in a cone mixer or the like, as in the processes previously cited.” And the testimony of those who made the discovery and made the disclosure shows that the way, and the only way, they discovered and disclosed, was a definite kind of agitation, and that this definite kind of agitation made their disclosed process workable. Indeed, that maximum of agitation and minimum of oil, increase of agitation and decrease of oil, were axioms in this process is made clear by the proofs. As the amount of oil was decreased, the amount of agitation had to be increased. In that regard, Sulman, one of the patentees (volume 1, p. 53), says:
. “The first requisite of any oil concentration process is to obtain efficient contact between the oil and the mineral and suitable methods must be employed to effect .this. Where the oil is in large relative quantity to the mineral, violent agitation is unnecessary,.and may be very harmful. With decreasing proportions of oil more vigorous agitation or mixing is necessary to insure such efficient contact of oil ivith the mineral particles. The agitation may therefore be said to be roughly proportioned to the work to be done in bringing about contact between large or small quantities of oil in regard to the mineral.”
His evidence (page 54) is that in the Gabbett mixer of the cone type he first saw produced the froth of the specification:
“The apparatus that I first saw the agitation froth produced in as described on the specification referred to was the ordinary Gabbett apparatus consisting of a vessel with rotating cone and with suitable baffles. The cone was rotated at a high rate of speed, about 1,000 revolutions per minute.”
*785The use oí the ordinary speed of the Gabbett mixer to effect the intermingling' of the oil with the mineral particles, and the use of super-added speed for the purpose of entraining air and producing froth, is made clear by the testimony of Picard, another of the patentees. Thus (page 109) in answer to the question:
“Q. In carrying out the process which the patent in suit purports to disclose, is there anything distinctive about the mode of agitation of the oiled pulp as compared with the agitation used in applying the Oattermole process, wherein the purpose is to granulate and precipitate the valuable mineral?”
—Picard says:
“In actual fact the same apparatus was employed for both purposes during my connection with the experimental work on the two processes. In the patent in suit it is more essential to beat in air, which is not an important point, and rather to be avoided, in the Oattermole process, where the object was only to mix thp various ingredients, air not being one of them.”
And he adds (page 110):
“We already knew from the first test that the cause was due to reducing the quantity of oil much below that hitherto employed, and observation of the -froth clearly indicated that the air which had been beaten in played an important and essential part in the production of this new idienomenon. I presume that further investigation wor’k was carried on, but in my opinion the invention may be said to have been completed after that first operation. * * * I had no idea, prior to this, that by reducing the quantity of oil to the limits which were used in this experiment that such a result would be obtained. I, of course, knew that air would float mineral, previously oiled; hut it was not anticipated by me hitherto that this particular result would be obtained if air were beaten in, in the manner in which it was done in making this test.”
John Ballot, the third patentee, also emphasizes (volume 1, p. 118) this “intentional beating in of air” caused by violent agitation, where in answer to the question:
“And when you saw the work in progress from March 1, 1905, onwards, as referred to by you in your answer to question 29, was this the first occasion upon which you had been informed as to the use in an oil flotation process of the intentional beating in of air for the purpose of promoting flotation?”
—he says:
"The intentional beating in of air to produce or promote the flotation of froth which was developed by that process was certainly not known until the fact had been actually discovered by using a very small quantity of oil, say 0.2 or 0.1 per cent., and agitating' it for a certain time, and then leaving the mixture to stand that the whole froth rose to the surface. By ’discovered’ I mean until the experiments had established the fact that this extraordinary idienomenon was every time reproduced by using the small quantity of oil, violently agitated, and then leaving it to stand, when the ininei’al rose to the surface in the form of dense froth.”
He adds:
“We considered it established, and that the principal cause of flotation, or perhaps the entire cause of flotation, was due to air beaten into the pulp, assisted, of course, by the other agents.”
Indeed, the discovery of beating air by agitation into the pulp as the groundwork of the discovery, and therefore of the resultant disclosure, is summed up by the witness Ballantyne (volume 1, p. 225) in the words:
*786“After violent agitation in such a way as to introduce air into the pulp, the agitation lasting several minutes, the pulp was brought to rest and immediately a coherent and persistent froth rose to the surface. Although I was closely familiar with all the earlier processes of ore concentration in which oil had been used, * * * the production of this agitation froth was to me little short of a miracle.”
In this development it will be seen, that Mr. Ballantyne makes the violent agitation of tire cone mixer the basic step in these words.
But not only was the testimony of these witnesses that this air-beating or air-entraining agitation was the agency which produced a froth of a hitherto unknown type, but we have the authoritative view of the Supreme Court that the lifting fprce of the bubbles is to be found not in the quantity of oil used, but in the maximum of agitation, “greater than and different from that which had been resorted to before.” We think the agency of this air-beating-in agitation as the functional cause of air flotation, is made clear by the Supreme Court. In that regard that court says:
“The small amount of oil used makes it dear that the lifting force which separates the metallic particles of the pulp from the other substances of it is not to be found principally in the buoyancy of the oil used, as was the case’ in prior processes, but that this fact is to be found, chiefly, in the buoyancy of the air bubbles introduced into the mixture by an agitation greater than and different from,- that which had been resorted to before and that this advance in the prior art and the resulting froth concentrates so different from the product of other processes make of it a patentable discovery as new and original as it has proved useful and economical.”
In quoting and approving the decision of the House of Lords, 27 R. P. C. 33, the Supreme Court alluded to the dual functional capacity of the patentees’ agitation: First, as a mixer of oil with the mineral particles (the function of Gabbett agitation at normal speed); and, secondly, the formation of air cells by air entraining (the function of Gab-bett agitation at abnormal speed). The extract thus quoted with approval from the English decision, is:
“They [the patentees of the Agitation Froth Process of the patent In suit] are not promoting a method of separation which had been before described, but they are engaged upon a new method of separation. Istead of relying upon the lesser specific quantity of oil in bulk they rely upon the production of a froth by means of an agitation which not only assists the process of minute quantities of oil reaching minute particles of metal, but forms a multitude of air cells, the buoyancy of which air cells, forming around single particles of the metal, floats them to the surface of the liquid.”
And that agitation of a particular kind, and not agitation of any kind, was the disclosure of the specification, is shown by Dr. Liebman, who says:
“I believe that 500 or 600 revolutions are quite sufficient for the Oatter-mole process (metal sinking). But I believe that at least 1,200 revolutions per minute are necessary for the process of the patent in suit in the same apparatus.”
From the above review, it is clear that the basis of this invention was agitation, and of agitation of a particular type and power, and that such type and kind of agitation gradually led to the further discovery that all oil, except the minimum required for mineral coating, could not be dispensed with. That the invention cannot be based on the *787use of a minimum of oil alone is clear, lor the stress laid on agitation in the specification, and its presence as an element in the claim hero in issue, forbid any such holding, and the further fact that a claim based wholly on the use of a fraction of 1 per cent, of oil for coating minerals was abandoned during the prosecution of the patent, to wit:
“The process of concentrating powdered ore which consists in separating the minerals from gaugue by coating the minerals with oil in water containing a fraction of 1 per cent, of oil on the ore, and recovering the oil-coated minerals.”
Seeing, then, that no change occurs in the character of the oil itself, in the amount required to coat the metal particles, or the affinity of the particles when coated, it follows that the essence of this patent lies in the agitation by which this low percentage of oil is made available. Now, what was the nature of this agitation ? It had a number of characteristics :
First, it was produced by machinery of high power operating on mechanism revolving at high speed. This mechanism was a special type; i. e., a top-inlet or cone Gabbett mixer which embodied certain features, each of which was necessary to the successful working of the invention disclosed: (a) The application of the mixer to the pulp was confined to such restricted zone of the pulp as was inside the cone; (b) to this cone-restricted zone the air had access; (c) the speed of the agitation was raised to a hitherto unused point; (d) the air in the chamber was by the speed of the agitator beaten into the pulp segregated in the cone; (e) in addition to high speed, time was required, tho agitator being revolved from 2% to 10 minutes before the entrance of air appeared in froth; (f) the agitator was of such novel, individual, and inventive character as to warrant the grant of a patent; (g) the agitator was of such special type aud speed that the froth it produced was also of a new type, or, as the Supreme Court said, “utterly different from any froth known before.”
But, because the claims here in controversy use the word “agitation,” without description or limitation, it is argued that the term should be used in a broad, generic sense, and cover any and every agitation which results in the air flotation of mineral coated particles. Put into practical commercial application, this means a monopoly of the principle of air flotation of oil-coated minerals, with the one exception, namely, where 0.1 per cent, or more of oil is used. To our mind, this use of the literalism and verbiage of this one word “agitation” to foreclose this whole great controversy loses sight not only of the spirit of the patent law, but also of the principles on which this contract — for a contract with the government is what this claim is — should itself be interpreted, for in construing that contract we must construe it as a whole; that is, the claims plus the specification, and not the claims minus the specification. We must also consider the claims in the light of the evolution of experiment that led up to the discovery, and consequently to the disclosure.
It is argued here that no sort of agitation is specified in the specification, that the phrase or idea of beating in air is not even mentioned in the specification, that there is no mention of any specific form of agi*788tation, and that therefore there is no qualification or limitation to be given to the type or kind of agitation. But this loses sight of the fact that the patent is based on the Cattermole process, and that that process and the patentees used a Gabbett mixer, and when the word “agitation” was used in the specification it referred to what the patentees had used in making their discovery, and was well understood by persons versed in the art, and when they spoke of the production of froth by agitation they meant precisely what they reported in their experiments, to wit:
“The froth produced is not due to any action of the acid circuit upon traces of calcite present in the ore; i. e., not to the liberation of any gas in the charge by means of the dilute acid employed in the circuit. It has been located, on the contrary, to the air introduced, by the Gabbett cone during agitation, the air attaching itself to the oiled mineral slimes and to a large proportion of the coarse mineral particles, although both, these materials can only be coated, with an infinitesimal amount of oil; i. e., oleic acid. That the formation of froth is due to air inclusions during the agitation, and not to carbonic acid or sulphuretted hydrogen, is proved by the following experiences.”
It is quite evident not only that this was the precise word and the disclosed sort of “agitation” they had in their minds when they disclosed their discovery. Moreover, we think that courts and judges have held this was the meaning of “agitation.” In passing upon the validity of the patent, the Supreme Court explained what the patentee’s invention was, and defined the agitation of that discovery as “beating the air into the mass.” This beating of air into the mass by the Gabbett mixer be.ing the sense in which that word was used in the specification, and no disclosure or suggestion of any other agitation being made, the burden is certainly on the patentees to show that, when the word “agitation” was used in the claim, it meant anything else than the agitation disclosed in the specification, to wit, that of the Gabbett mixer or its substantial equivalent. For the word “until,” in “agitating the mixture until,” aptly described the “two and a half to ten minutes” of the directions of the specification during which a Gabbett mixer was to be operated before the froth was produced. In so holding, we do not minimize, belittle, or underrate the very important discovery these inventors made. But the great discovery they disclosed was based on two facts — oil of a certain kind, and agitation of a certain kind. The quantity of oil was less than a tenth. The agitation was by beating in the air until a froth came. That was the extent of their discovery, their disclosure, and their claim. Within those limits they are entitled to protection. Beyond that the art has a right to progress and improve.
So regarding the claim, we turn to the defendants’ plants, as to first of which, namely, the one in operation when the bill was filed, there can be no question. It is simply a replica of the plaintiff’s process, used as a Gabbett mixer, as did Hyde in the case in the Supreme' Court, and, so far as it is concerned, infringement, and an accounting should be decreed. But as to the defendants’ second plant I cannot agree that the claims in question cover it. I shall not enter into a detailed description of its working, but at present restrict myself to saying that the basic feature of the defendants’ process is the sub-aeration of the pulp through the agency of compressed air. There is no air expansion as an agitating agency in plaintiff’s process. They beat *789no air into the pulp; they introduce compressed air into the pulp, and avail themselves of the instant expansion of that air to form a different kind of bubble from that of the patentees, and they get a different kind of froth. And the crux of the case may, as we view it, be stated in this way: If the defendants were applying for a patent for concentrating ore, which consisted in sub-aerating a mixture of ore and a fraction of 1 per cent, of oil through the agency of compressed air, would such process be anticipated by the plaintiffs? The test of that question is, not whether the product of twoi processes is the same, but whether the steps of the two processes are substantially the same. Addressing ourselves to that question, I have reached the conclusion that the defendants’ process approaches the problem in a wholly different line from the patentees, and, while the result is the same, that result is reached by steps or means acting in a different way and by a different method. Physically the defendants’ method substantially and functionally consists in the liberation of air under light pressure, seven pounds’ compression, into the pulp mixture. Physically, by the turn oí a stopcock this light pressure is turned on, and instantly aeration and bubble forming begins, and agitation follows. The physical difference between the two systems is as striking in its way as it- would be if a person, standing on the stern of an ocean steamer and seeing the maelstrom caused by the 100 a minute revolutions of a screw, should be told that these revolutions, the screws themselves, the shaft, and the ship’s great engines, could be taken out of the ship, and their places supplied by a tank of air under mild compression. And yet that is just what these defendants have done. They have eliminated, not 100, but 1,000, revolutions a minute of the Gabbett mixer; they have eliminated the shaft, couplings, and power machinery which was necessary to actuate this; and for it they have substituted the stopcock of a tank filled with air under light compression. Defendants have eliminated such a distinctive element of plaintiff’s process that it was patented. The physical difference between the means employed is well illustrated in this way: Suppose the owner of the Gabbett agitator were to sue the defendants for infringement by the use of a compressed air apparatus; could an expert be found so rash as to even suggest that the two were substantially equivalent? Not only are the two not mechanical equivalents, but it is evident that in the two processes the Gabbett mixer and the compression tank work on wholly different principles. The Gab-bett mixer uses agitation to beat the air in, in order to thereafter produce bubbles; and that only after several minutes’ work produces bubbles, and these bubbles only rise after the several minutes’ agitation -goes on. In other words, in plaintiff’s process bubbles are the product of agitation. In the defendants’ practice the expansion of the air itself, on its release from compression, at once creates bubbles, and the instant rise of these bubbles to the surface at once sets up agitation. In other words, the defendants’ bubble causes agitation, while in the patentees’ agitation causes bubbles. In the one there is a gentle agitation of the fluid, caused wholly by the expansion of air when released from compression. In the other there is no expansion of the air; it is simply beaten into the mixture by the action of the arms of the Gab-bett mixer. In the plaintiffs’ process the agitation forms the air cells, *790and only after several minutes’ physical exertion; in the defendants’ the air, on its release from compression, by its own inherent power, forms the cell, and forms it instantly.
It. has been suggested that in defendants’ process the air is shot into the mixture like a bullet from a gun, and that there'is no difference between shooting air into a mixture with a gun and beating it in with a paddle. But it is manifest that the defendants’ practice is not the shooting in of a violent air blast, but is in allowing air under slight compression to escape from such slight compression at the bottom of the tank. To have the compressed air strike the top surface of the pulp would not lead to any bubble introduction, and" consequently to no subsequent agitation by rising bubbles, for such bubbles as would be formed would already be near the surface. It will thus be seen that the introduction of compressed air is necessarily made at the bottom of the pulp vessel, and it is also apparent that no such sub-air introduction, which characterizes the defendants’ process, could be effected by the Gabbett beating in of the air, for in such case the moving blades of the mixer would haye to be wholly immersed in water, and, as we have seen heretofore, such immersion forbade the use of the top-outlet form of Gabbett agitation shown in Figure 1. These differences in form and principle, the difference between a hurricane and a zephyr, the spread between the maelstrom action of a swift-moving mechanism and the bubbling, seeping action of air released from compression at the foot of a tank, and then in the case of the Callow cell oozing or seeping its way between the threads of a canvas, are so different in degree of violence and mode of action that one would naturally expect some difference should evidence itself in their product.
And such is the case. In the defendants’ process the bubbles rise at once to the surface; but they are so frail that they absolutely require the continuous support of other bubbles. For in case the air is shut off below, and the upward bubble stream stops, those on the surface at once disintegrate. The defendants’ bubbles are ephemeral; they are matured at birth; and, like all such creations, lack self-sustaining power. On the other hand, the plaintiffs’ bubbles evidence themselves at the surface .in a froth which is only formed after from 2,500 to 11,000 revolutions of the mixer (2% to 10 minutes of 1,000 to 1,100 revolutions), but when so gradually formed are so self-sustaining that they last for days and are so tough that they support a shovel. If the production of such froth by such a protracted and violent agitation was a contribution of inventive and novel worth to ore concentration, and apart from all authoritative decision that is our estimate of the goal it reached, then for another to reach that same goal without making the tough, persistent, shovel-carrying froth, and without using the thousands of revolutions of powerful machinery, absolutely required to produce it, is also a contribution of inventive and equal worth to ore concentration. And the best evidence of its worth, of its simplicity, and of its effectiveness is the fact that the plaintiffs themselves use it and concede its superiority. Concededly valuable as sub-aeration is, it is certain the ore-concentration art never would have had it, if we were dependent on the plaintiff’s patent to give it to the art. Not only did the patent in suit not disclose it, but, if anything, their disclosure *791pointed away from rather than to the probability of the use of compressed air. Thus in their specification they take pains to avoid the imputation even of using gas as a flotation agency, and ex majore cautella give notice that “it is to be understood that the object of using acid in the pulp according to this invention is not to bring about the generation of gas for the purpose of flotation thereby” — a statement the Supreme Court referred to as evidencing that their work tended not in the line of introduction of gas, but “to the presence of the air introduced into the mixture by the agitation which had been resorted to, to mix the oil with the particles of crushed ore.”
Indeed, that the use of compressed air with their concentration process was not in the patentees’ concept is strikingly shown by the fact that, had they had any such use in view of the power of compressed air to do the work of the Gabbett mixer, their suggestion of the possibility of its use was almost challenged by ihe use to which they suggested it could be put to in the second and third spitzkasten, where no mixing or separation was required. They there say:
“An alternative method for the recovery of any sunk oiled metalliferous matter which may be deposited in the second and third spitzkasten is as follows: The producís suspended in circuit liquor are removed from the spitzkasten and placed in a vessel in which they are submitted to an additional pressure of air or other gas of from, say, one to two atmospheres or over. On relief of such pressure the bubbles of air or other gas so generated throughout the mass at once sweep to the surface thereof all tho metalliferous matter in the form of a froth which can bo separated as before. This idea is not claimed broadly in this case, hut forms the subject-matter of an application, liled by us on January 9, 19060, serial No. 295,820.
Of course, whatever ideas they had on the subject were embodied in another application, and offered no basis for a claim in this patent; but even this suggested use of compressed air as a flotation agent to these experienced men suggested to them no use of that agency in the 2>rocess of this patent. It remained for some other engineer, in this case the defendants’ experimenter, to discover and disclose it. This view is emphasized by the fact that five years after this patent was applied for, and two years after it became the owner of it by assignment, the plaintiff joined with one Hoover in applying for a British patent for such use of compressed air. In that patent the patentees themselves emphasize the points we have made, .saying:
“This method of introducing the gas may have three functions: (I) The gas may bring about the necessary agitation of the mass. (IX) The gas, being in a state of very line division, is effectively brought into contact with every mineral particle, thus clearly differentiating the process from that of the patent where the mechanical stirrers caused the agitation and thus preceded bubbles, while here bubbles preceded and caused agitation.”
In the patent in suit the mechanical action of the stirrers, kept up for ten minutes, brought about air being brought into contact with the mineral particles, while by the subgaseous process, the gas being in a state of fine division through seeping through the canvas, is, as said above, “brought into contact with every mineral particle.” The fact that the present plaintiffs, five years after the grant of the patent, joined Hoover in taking out this patent, in itself shows that it then re - garded the sub-air process as one not covered by the patent in suit, and *792may well cause a court to hesitate to give a construction to the patent in suit which is at variance with the plaintiffs’ conduct in taking out this Hoover patent.
To me it seems clear that the field of discovery the patentees disclosed was not the broad principle of air flotation, for concededly that principle was known before. What they did disclose was an original'method of using the broad principle of air flotation in a particular way. That method was by beating air into pulp with a minimum of oil. They showed how the beating in of air could be effected, and they showed a novel froth product as. a result of this beating-in process. In their process air was the product of agitation, and not the agitating agent. In their process bubbles did not appear until protracted agitation was ended. Not only was it produced by agitation, but it did not appear until agitation ceased. It will thus be seen that air was in no way an agitation agency in the plaintiffs’ process, in its specification, or in its claims; but the agitation disclosed therein was wholly the physical agitation of an extraneous mechanical process. Now, this occupancy of the field of air flotation, novel, Useful, and inventive, the plaintiff disclosed and should be awarded. But, by occupying this part of the field, the process of entraining air by mechanical beating in, the plaintiff did not foreclose all further advance in air flotation. Air flotation as . a recognized principle was known before this patent, and by discovering one way to utilize that principle the patentees did not bar all other ways of making use of that principle. If they had discovered the broad principle of the capacity of oil to coat minerals and to reject gangue, if they had first discovered the coating of air bubbles with oil, if they had first shown that oil-coated minerals and oil-coated bubbles would unite and rise to the surface, we could regard them as first comers into a newly discovered field, and as entitled to make all further progress in that art servient to those who created it. And while this has been done in some notable instances, it is nevertheless true that even great and notable steps in a great art can be disclosed by patentees without blocking all furthér progress in that field. In that regard we are admonished by the later rulings of the Supreme Court in patent causes, which began with Westinghouse v. Boyden, that even such a great invention as the instantaneous stoppage of every car on a great freight train, an invention which is at the bottom of the movage of tonnage to-day, did not bar other inventors from showing other means of using air to accomplish the same result. And such holdings as Westinghouse v. Boyden and the like seem to us the true principle which should govern the administration of the patent •law, namely, giving full protection to the full limit of the disclosure made, and refusing to extend that limit so as to bar further advance by others. Applying that principle to the present case, I would hold that the step of the process “agitating the mixture until the oil-coated mineral matter forms into a froth” meant the novel air-entraining agitation which the patentees disclosed and did not cover the novel air-releasing agitation which the defendants disclosed.
In accordance with these views, and in support thereof, I am constrained to record my respectful dissent to the opinion of the court.