vision of a specification by erasures made L. ed. 426; Stow v. Chicago, 104 U. S. 547, under the guise of a disclaimer. Union Metallic Cartridge Co. v. United States Cartridge Co. 112 U. S. 624, 28 L. ed. 828, 5 Sup. Ct. Rep. 475; 15 Am. & Eng. P. C. 367; Hailes v. Albany Stove Co. 123 U. S. 582, 31 L. ed. 284, S Sup. Ct. Rep. 262; Collins Co. v. Coes, 130 U. S. 56, 32 L. ed. 858, 9 Sup. Ct. Rep. 514; Hurlbut v. Schillinger, 130 U. S. 456, 32 L. ed. 1011, 9 Sup. Ct. Rep. 584; Sessions v. Romadka, 145 U. S. 29, 36 L. ed. 609, 12 Sup. Ct. Rep. 26 L. ed. 816. Improvement in degree by substituting one old material for another old material is not invention. Hotchkiss v. Greenwood, 11 How. 248, 13 L. ed. 683. Mere change in size, weight, form, proportion, and shape, without change in funetion, is not patentable. Phillips v. Page, 24 How. 164, 16 L. ed. 639; Smith v. Nichols, 21 Wall. 112, 22 L. 799; Grant v. Walter, 148 U. S. 547, 37 L. ed. ed. 566; Dalton v. Jennings, 93 U. S. 271, 552, 13 Sup. Ct. Rep. 699; Torrant v. Du- 23 L. ed. 925; Pomace Holder Co. v. Ferguluth Lumber Co. 30 Fed. 830; Rumford son, 119 U. S. 335, 30 L. ed. 406, 7 Sup. Ct.. Chemical Works v. Lauer, 5 Fish. Pat. Cas. Rep. 382; Milligan & H. Glue Co. v. Up615, Fed. Cas. No. 12,135; White v. E. P. ton, 97 U. S. 3, 24 L. ed. 985; Estey v. BurGleason Mfg. Co. 21 Blatchf. 364, 17 Fed. dett, 109 U. S. 633, 27 L. ed. 1058, 3 Sup. 159; Albany Steam Trap Co. v. Worthing- Ct. Rep. 531; Peters v. Active Mfg. Co. 120 ton, 25 C. C. A. 258, 51 U. S. App. 164, 79 Fed. 966. This court has never permitted itself to hesitate in affirming the rights of the publie to continue the use of any known process, because of real or alleged discoveries of peculiar advantages in such use. Lovell Mfg. Co. v. Cary, 147 U. S. 623, 37 L. ed. 307, 13 Sup. Ct. Rep. 472; Roberts v. Ryer, 91 U. S. 150, 23 L. ed. 267; Ansonia Brass & Copper Co. v. Electrical Supply Co. 144 U. S. 11, 36 L. ed. 327, 12 Sup. Ct. Rep. 601. See also Wood-Paper Patent, 23 Wall. 566, sub nom. American Wood Paper Co. v. Fiber Disintegrating Co. 23 L. ed. 31; Blake v. San Francisco, 113 U. S. 679, 28 L. ed. 1070, 5 Sup. Ct. Rep. 692; Burt v. Evory, 133 U. S. 349, 33 L. ed. 647, 10 Sup. Ct. Rep. 394; French v. Carter, 137 U. S. 239, 34 L. ed. 664, 11 Sup. Ct. Rep. 90; Busell Trimmer Co. v. Stevens, 137 U. S. 435, 34 L. ed. 723, 11 Sup. Ct. Rep. 150; United States Mitis Co. v. Carnegie Steel Co. 89 Fed. 343; Falk Mfg. Co. v. Missouri R. Co. 43 C. C. A. 240, 103 Fed. 295. The "Furniture Spring" case, Lovell Mfg. Co. v. Cary, 147 U. S. 623, 37 L. ed. 307, 13 Sup. Ct. Rep. 472; and the "Glue Soup" case, Leggett v. Standard Oil Co. 149 U. S. 287, 37 L. ed. 737, 13 Sup. Ct. Rep. 902,are controlling of the present issue. U. S. 530, 32 L. ed. 738, 9 Sup. Ct. Rep. 389; Grant v. Walter, 148 U. S. 547, 37 L. ed. 552, 13 Sup. Ct. Rep. 699; Morgan Envelope Co. v. Albany Perforated Wrapping Paper Co. 152 U. S. 425, 38 L. ed. 500, 14 Sup. Ct. Rep. 627; Wright v. Yuengling, 155 U. S. 47, 39 L. ed. 64, 15 Sup. Ct. Rep. 1; American Road Mach. Co. v. Pennock & S. Co. 164 U. S. 26, 41 L. ed. 337, 17 Sup. Ct. Rep. 1; Busell Trimmer Co. v. Stevens, 137 U. S. 423, 34 L. ed. 719, 11 Sup. Ct. Rep. 150; Consolidated Roller Mill Co. v. Walker, 138 U. S. 124, 34 L. ed. 920, 11 Sup. Ct. Rep. 292; Marchand v. Emken, 132 U. S. 195, 33 L. ed. 332, 10 Sup. Ct. Rep. 65. *Mr. Justice Brown delivered the opinion [410] of the court: Steel is a product, or, perhaps, more accurately, a species of iron, refined of some of its grosser elements, intermediate in the amount of its carbon between wrought and cast-iron, and tempered to a hardness which enables it to take a cutting edge, a toughness sufficient to bear a heavy strain, an elasticity which adapts it for springs and other articles requiring resiliency, as well as a susceptibility to polish, which makes it useful for ornamental and artistic purposes. Pig iron, which was the original basis for the manufacture of all iron and steel, is made by the reduction of iron ore in large blast furnaces, which are filled with layers of ore, charcoal or coke, and flux. By the The application of an old process or machine to a similar or analogous subject, with no change in the manner of application and no result substantially distinct in its nature, will not sustain a patent, even if the agency of this the iron is melted out and new form of result has not been contemplated. Pennsylvania R. Co. v. Locomotive Engine Safety Truck Co. 110 U. S. 490, 28 L. ed. 222, 4 Sup. Ct. Rep. 220; Miller v. Foree, 116 U. S. 22, 29 L. ed. 552, 6 Sup. Ct. Rep. 204; Brown v. Piper, 91 U. S. 37, 23 L. ed. 200; American Road Mach. Co. v. Pennock & S. Co. 164 U. S. 26, 41 L. ed. 337, 17 Sup. Ct. Rep. 1; Mast, F. & Co. v. Stover Mfg. Co. 177 U. S. 485, 44 L. ed. 856, 20 Sup. Ct. Rep. 708. Generally, improvement in degree is not patentable. Roberts v. Ryer, 91 U. S. 150, 23 L. ed. 267; Dunbar v. Myers, 94 U. S. 187, 24 L. ed. 34; Crouch v. Roemer, 103 U. S. 797, 26 falls to the bottom of the furnaces, is drawn out through openings for that into canals, and finally into purpose molds, where it solidifies into what are termed pigs. Prior to the invention of Sir Henry Bessemer, steel was manufactured from a pig-iron base by a tedious and expensive process of refining in furnaces adapted to that purpose. The process was so costly that steel was little used except for cutlery and comparatively small articles, and was practically unknown in the construction of bridges, rails, buildings, and other structures where large quantities of iron were required. In 1856 Bessemer discovered a process of purifying iron without the use of fuel, by blowing air through a molten mass of pig iron placed in a refractory lined vessel called pola furnaces was drawn off into such resera converter, whereby the silicon, carbon, voirs, which were made large enough to and other nonmetallic constituents were hold the product of two or three furnaces, consumed, and the iron thus fitted for im- and from which the molten metal was with mediate conversion into steel by recarbonization. The present process of recarbonization was a supplementary invention of Mushet, who accomplished it by the introduction of ferro-manganese, or spiegel-eisen, while the iron in a molten state was issuing from the converter, in which it had been purified, and was thus converted into steel. The process of running molten metal from blast furnaces into pigs and remelting them in cupola furnaces for use in a converter was termed the indirect process, and was generally used prior to the Jones invention. (411] *His process is thus described by Bessemer in his patent of 1869: "The most important of these operations consist in melting the pig metal, transferring it in the molten state to the converting vessel, blowing air through it, and converting it into a malleable metal, mixing the metal so converted drawn into the converters. Had the amount required for the converters in each case been the exact product of one or more cupolas, no reservoirs would have been necessary, but as the demand was variable, a storage of molten metal was required to retain the product of one or more cupolas, until it was required for the converters. Of course, as the product of two or more furnaces was drawn off into these receiving ladles, there would be some intermixing of those products, although the receiving ladles do not appear to have been used for that purpose, the operators relying more particularly upon the careful selection of pigs beforehand, to obtain the requisite uniformity for conversion into steel. The ladles being open at the top, the molten metal could not long be retained in them, and in the best practice it was so arranged that with a certain quantity of fluid mangane- the withdrawals from the reservoir were sian pig iron, pouring the mixed metals into a casting ladle, and running it from thence through a suitable valve into ingots or other molds, and the removal therefrom of the ingots or other cast masses when solidified." This invention of Bessemer, simple as it appears, may be said not only to have revolutionized the manufacture of steel, and to have introduced it into large constructions where it had never been seen before, but to have created for it uses to which ordinary iron had been but illy adapted. While in the Bessemer specification of 1856 it is said "the iron to be used for the purposes of my present invention may be conveyed by a gutter in a fluid state direct from the smelting furnace where it has been obtained from the ore," without the expense and delay incident to the intermediate cupo la process, practical experience, in this country at least, showed that the refining of iron without first casting it into pigs, selecting or mixing the pigs, and remelting them, was attended with such expense that the entire abandonment of the practice was seriously considered. The difficulty was in the material variations between different portions of the same cast, and even differ- made every few minutes, and without regard to the amount left in the reservoir after each withdrawal. It will be borne in mind that the object in either case, whether by direct or indirect process, is to obtain, as far as possible, a uniform product of iron for the converter. "These results," said one of the witnesses (Kennedy), speaking of the process used before that of Jones, "are not obtained by the practice of taking metal from two blast furnaces by running a train of ladles in front of them and tapping into each ladle half a charge and following it from a second furnace. By such practice, of course, there is some independent equalization of the composition of each ladle or of the ladles of each group, but it affords no further advantage, and in fact would not obviate the dif ficulties of direct metal working. It does not enable the converter manager to foretell the character of each charge from the character of the preceding charge, and would therefore entail the uncertainties of opeгаtion and the irregularity of the product which the Jones method avoids." It had long been an object of manufacturers that steel should be made directly from the molten metal, as it comes from the blast furnaces, without having to pass through the intermediate or cupola process, which [413] involved the casting of the furnace metal into pigs. These, after becoming cold, were assorted, broken up, recharged and remelted in a cupola furnace, and then placed in a converter for conversion into steel. By this cupola process a product, practically uniform in character and suitable for further treatment in the converters, was secured, but at the expense (more than 60 cents per ton) of rehandling and remelting the iron as it came from the blast furnaces, in cupo These irregularities were in a measure las, and the contamination of the metal obviated, not only by a careful selection of with sulphur evolved from the coke in the pigs beforehand, but by the necessity of process of remelting. The obstacles conemploying open receiving ladles or reservoirs nected with this method and the difficulties [412]into which the product of one or more cu-attendant upon the use of the direct process are thus comprehensively set forth by Mr. Julian Kennedy, one of the experts: "Ever since the invention of the Bessemer process it has been well recognized that great economics could be attained by transferring the molten metal from the blast furnace to the converter without allowing it to solidify. Until within a few years, however, this direct process, as it has been called, has not been generally used. It is easy to see why this was the case. The fluctuation in the chemical composition of the metal from the blast furnace was too great to allow that degree of uniformity of product in the Bessemer steel produced from it which is absolutely necessary in the case of steel rails, for example, which must be as reliable as human skill can make them, and where no reasonable expense can be spared to make them perfectly safe and trustworthy. A very few broken rails in a track, with the damage to property and human life which this might cause, would far more than offset any possible saving in a year's work, due to the use of the direct process. For this reason the practice, until within comparatively recent years, has been to cast the metal in pigs, then to analyze imately the theoretical advantages of the "Fourth. The obvious remedy is to mix a "A few words of history may be of interest. Mr Bessemer's early intention was to use blast-furnace metal direct. The earlier Bessemer practice, especially that in Sweden, was with metal right from the blast furnace. But this practice did not make headway, except where there was from 3 to 5 per cent of manganese in the pig blown, for reasons just mentioned; *so that[415] while it soon became standard at Terrenoire and elsewhere in France, as well as in Sweden, and to some extent in Germany, yet in England it was not only unused, but pronounced impracticable so late as September, 1874." This difficulty, and it seems to have been it and reject any portion not closely approx- so serious as to render the direct process imating a rigid specification in its chemical commercially impracticable,-Jones sought composition, and to select, mix, and then to remedy, and did remedy, by creating a melt the the approved metal in cupola furnaces. By this means very great uniformity of chemical composition of the remelted metal can be obtained, and good and reliable steel made from it with regularity and certainty." covered reservoir of molten metal between the blast furnaces and the converters, in which should always be maintained a large quantity of metal, happily termed by the district judge a dominant pool, which should be drawn off in small quantities at a time, and replenished by a like quantity of metal from the blast furnaces. In this way, while the metals taken from the several blast furnaces might differ in their heat and constituent elements, yet, being received and mixed with the molten metal in the dominant pool, they were, when discharged from the reservoir, approximately, though not perfectly, uniform, the original variations having been lost in their mixture with the dominant pool. "It is therebe better to go to the expense of building opinion, "that with a mixer thus operated, and using cupola furnaces. We did not it is possible to have wide variations in the then perceive any means adequate to overcome these disadvantages." 44] Speaking of a time when the direct process (before that of Jones) had been in use for several years, he said: "After studying the results which had been obtained at the Edgar Thomson works and elsewhere in the use of the direct process, I consulted with Mr. James Gayley, and we agreed that in the building of a new works it would not be profitable to use direct metal, but that, on the contrary, the disadvantages resulting from the irregularity in the product were so great that it would fore plain," says the district judge in his The difficulties connected with the prior devices are also stated in an article by Mr. Holley, published in 1877, from which we extract the following paragraph: "Third. The embarrassing feature of the direct process is the irregularity in the heat -that is to say, in the silicon of the charges - resulting in the large amount of scrap due to too little of this element, and in the increased number of second-quality rails due to too much of it; while in France, where 3 to 5 per cent of manganese is the heating ingredient, there may always be an excess of this latter element without injuring the quality of the steel, although the variation of heat is here, also, a serious difficulty. In other words, it has not yet composition of the blast furnace metal charges added, and at the same time the successive withdrawals for the Bessemer converter show quite small and gradual changes of composition. The heat of the detained mass is affected by the incoming charges just from the blast furnace, but the heat of such addition, whether relatively high or low, must mingle with, be modified by, and average with, the heat of the larger and dominating mass." It is not insisted that this method gave absolutely uniform results, "nor," says the witness Fry, "did the inventor, as I understood him. comprehend such, but, on the contrary, he recognized the practical impossibility of rendering uniform a continuous supply of metal, and desired only to reduce the abrupt changes of the several portions been practicable to work the blast furnace added to the gradual changes of the porwith sufficient regularity to realize approx- tions withdrawn, and this is what he worked out from his invention in a thor- | been abandoned. In regard to this the oughly practical way." witness Kennedy said: While the patent in suit is for a process, "The Jones method has made the direct and not for a mechanism, the process will process, which was attended with great be the more easily understood by a refer- danger and difficulties before the date of ence to the apparatus above reproduced, "his invention, a thoroughly practicable and [116] which consists of a *reservoir, or closed re- successful one. Instead of it being a ques"mixer," tion of great doubt whether to run the a ceptacle, commonly termed lined with fire brick of sufficient thickness to retain the heat of the molten iron, and of such size and strength as to be capable of receiving and retaining a large amount -"say, 100 tons" - of molten iron. This reservoir is mounted upon journals, and is adapted to be tipped so as to receive at one end molten metal from the blast furnaces, carried to it in cars, and by being tipped in the other direction, to discharge the same into similar cars, in which it is carried to the converter. The essence of the invention lies in the fact that the tip is so regulated by a stop that the reservoir can never be wholly emptied, but a "considerable quantity" of metal always remains, -a dominant pool, into which successive additions received. are That the invention is one of very considerable importance is attested by the fact that it was not only put into immediate use in the Edgar Thomson works at Braddock, then owned by the plaintiff, but has since been adopted by all the leading steel manufacturers in this country, and by many similar works in Europe, where the patent was sold for £10,000. Mr. Carnegie, one of the witnesses, says of it: "There were both advantages and disadvantages [in the direct process used prior to Jones's invention], but the disadvantages were so great that we often debated whether to abandon the process or not. We found it impossible to get a uniform quality of rails as well as by the cupola method. When we were told us that still anxiously struggling with the problem, and undecided whether to continue or abandon it, Captain Jones he believed he had invented a plan which would solve the problem. We thought so well of the idea-I was so convinced of its reasonableness-that I directed him to go ahead with his invention. Cap metal direct to the converter or remelt it, as it was up to the time of Jones's invention, no one would now think of building a new works containing both furnaces and converters without arranging to mix the metal by the Jones method, which not only effects an immense saving in the cost of operating the works, but enables a uniformly good product to be made, and also a purer product than can be obtained from cupola metal, which absorbs and is contaminated by sulphur from the coke which constitutes the fuel of the cupola." Indeed, the value of the process is not wholly denied, though much depreciated, by the defendant, which relies rather upon the fact that it was well known in the art, and that so far as it is described in the Jones specification and drawings it was not infringed by it. 1. We now proceed to an examination of the question of anticipation, in support of which a number of English patents are produced, which will be briefly considered: First, the British patent to Tabberner of 1856, the object of which was, as stated by the patentee in his specification, "to dispense with the necessity of employing one or more large furnaces, and to use in lieu thereof several small furnaces, the combined capacities whereof are equal to that of one or more large furnaces, and to cause these small furnaces to discharge their contents at short intervals of time into one large reservoir, from which the molten metal may be drawn for casting from. The *principal features in this invention [418] consist in directing the blast to the body or belly of the furnace, as well as to the hearth thereof, for the purpose of fusing or smelting the entire mass of ore in the furnace simultaneously, or nearly so. The mode hitherto practised in smelting furnaces has been to direct blasts into the ... tain Jones did so, and almost from that day hearth only thereof, thereby requiring sev our troubles ended. He had scored a mendous success; another step forward was taken in the manufacture of steel, and we are using the invention to-day. Without this invention I believe that we should have abandoned the mode of running direct from the blast furnace. Above all things, the manufacturer has to regard the [417] uniformity of product, *the equality of rails; and this uniformity cannot be obtained without Jones's invention, as far as I know." eral hours to smelt or fuse the contents of a large furnace." The specification is somewhat blind, and it is difficult to see what definite or valuable result is obtained by the use of several small instead of one large furnace, except, perhaps, a quicker heating and less delay in its practical operations; but it is sufficient for the purposes of this case to say of it that it contains no suggestion of a mixing of different casts for the purpose of obtaining a more uniform product, and that the invention has no relation to a further treatment or re fining. It does contemplate the use of a reservoir, but there is no suggestion of a It is true that what is termed the direct process was used in connection with the Bessemer invention in some foreign countries, notably Sweden and France, with reservation, in such reservoir, of a quantity more or less success, due to the peculiar of molten metal. It is not denied that the character of the ores used in those coun- use of a reservoir from which molten metal tries; but such attempts in this country may be drawn long antedated the Jones had proven practically failures, and had patent. But the best that can be said of ings." the Tabberner patent is that, if the reser- | quality of metal, substantially as hereinbevoir had been of sufficient size and properly fore described and illustrated by the drawconstructed so as to never be completely emptied, it might have been adapted to carry out the Jones process; but there is no evidence that it was ever so constructed, or that the production of a uniform discharge from the reservoir was contemplated. That it could not have been intended for the purpose of carrying out the Bessemer process, or any other process, for the use of blast-furnace metal in a converter, is evident from the fact that the patent was nearly simultaneous with the Bessemer patent, of the existence of which the patentee appears to have been entirely ig norant. The English patent to Deighton of 1873, for "improvements in the arrangement and mode of working an apparatus for the manufacture of Bessemer steel," contains the closest approximation to the principle of the Jones invention. If this does not anticipate, none does. The primary object of the patent seems to have been to prevent the loss of time while the converters are being cooled and relined or repaired, and 119] again *prepared for work, by providing that the converting vessel shall be so arranged that it can be readily detached from its actuating mechanism and lifted bodily out of its bearings by a suitable crane or other lifting mechanism, and a spare converter substituted in its place. There is, however, a further provision in the patent, as follows: "Instead of manufacturing Bessemer iron or steel from pig iron, which has been melted in cupolas, my invention also consists in taking the molten metal directly from the blast furnace to the converter, in which case I prefer to arrange the Bessemer plant in a line at a right angle to a row of two or more blast furnaces, and place a vessel to receive the molten metal tapped from two or more blast furnaces to get a better average of metal which will be more suitable for making Bessemer steel or metal of uniform quality, the vessel or receiver being placed on a weighing machine so that any required weight may be drawn or tapped from it and charged into the converter." The specifications provide for manufacturing Bessemer steel directly from the smelting furnace by employing gates or channels for molten metal from each fur nace, leading to a reservoir, which is placed low enough to give fall for the molten metal to flow from the blast furnace to this reservoir, which forms a receptacle for mixing the molten metal from two or more of the smelting furnaces. From the reservoir the mixed molten metal is tapped, and flows down the swivel trough into the converter. By placing the reservoir on a weighing machine, it can be readily ascertained when the exact quantity required has been tapped from it into the converter. The sixth olaim of the patent is for "the system or mode of arranging and working Bessemer converters with a receiver or receptacle for mixing the molten metal from two or more smelting furnaces to get a more uniform While Deighton seems to have conceived the idea that uniformity of product was necessary to the successful use of the direct process, and might be attained by mixing the discharge from several blast furnaces in an open reservoir, standing between *the[420] furnaces and the converter, the dominant idea of the Jones invention, that a constant quantity of molten iron should always be kept in such reservoir to serve as a basis for such mixture and an equalizer of the different discharges, does not seem to have occurred to him. As the discharge pipe was located at the bottom of the reservoir, it was certainly possible to empty it entirely, and the testimony in the case indicates that this was the natural method of operation. If this were so, then the reservoir accomplished nothing beyond the mixing of each batch of metal introduced into it from the different blast furnaces. There is nowhere in the specification a suggestion of supplying to and withdrawing from the reservoir small amounts at a time, a constant quantity of metal being retained in the reservoir for the purpose of equalizing the different products of the blast furnaces. While the Deighton reservoir, if a cover had been added to it, might perhaps have been utilized for that purpose, there is no evidence that such use ever occurred to the inventor. Indeed, the absence of a cover to the reservoir is evidence, even to a nonexpert, that it was not contemplated that a permanent quantity of molten iron should be retained in it, since a radiation of heat would thereby be produced and the contents skulled or crusted over with a layer of refuse iron or slag. The testimony is clear that the Jones process cannot be carried on in an open reservoir, and the absence of a cover is conclusive that it is not so used. It is insisted, however, that defendants have demonstrated, by practical experimentation with a plant constructed according to the specification of the Deighton patent, that the results are practically the same as those obtained by the Jones process. This plant, however, was constructed after suit brought, long after the Deighton patent had been allowed to expire, and with no opportunity afforded the plaintiffs to inspect the pla plant or witness its operation. The tank was fitted with a cover, and a constant pool of molten metal retained in it; but this was not the Deighton process, but the Jones process adapted to the Deighton device. Were this evidence admissible at all, we are satisfied that it is met by the fact that if the Deighton patent had been adaptable to the Jones process, it is scarcely possible that its merits should have failed[421] to seize upon the attention of manufacturers, who would have brought the patent into general use, instead of allowing it to lapse for the nonpayment of a comparatively small fee. As something in the nature of the Jones process was needed to enable steel to be manufactured directly from the |