of the safety-valve, with the means herein described for regulating or adjusting the area of the passage for the escape of steam, substantially as and for the purpose described."

The answers in the two suits set up want of novelty, and cite, as anticipating patents, three English patents: one to Charles Ritchie, No. 12,078, August 3, 1848; one to James Webster, No. 1,955, July 12, 1857; and one to William Hartley, No. 2,205, August 19, 1857; also an English publication made in 1858, called "The Artizan." Infringement is denied, and it is averred that the valves which the defendant makes and sells are the inventions of George H. Crosby, and are described in two patents granted to him, and owned by the defendant: one, No. 159,157, dated January 26, 1875; and the other, No. 160,167, dated February 23, 1875. The same proofs were taken in the two suits, and they were heard together in the circuit court. In each suit that court made a decree dismissing the bill, (7 Fed. Rep. 768,) and from each decree the plaintiff has appealed.

When Richardson applied for his patent of 1866 his claim read thus: "What I claim as my improvement, and desire to secure by letters patent, is increasing the area of the head of the common safety-valve, outside of the ground joint, F, F, and terminating this addition with the circular or annular flange or lip, c, c, constructed in the manner, or substantially in the manner, shown, so as to operate as and for the purpose herein described." This claim was rejected as defective, because not for a device, and it was amended to read as granted.

In this application for the patent of 1869 there were two claims. The second related to means for preventing the guides and stem of the valve from binding, and was rejected as not new, and stricken out, though the descriptive matter on which it was founded was retained. The first claim, as applied for, was this: "What I claim as new, and desire to secure by letters patent, is combining with the surface beyond the beveled, or equivalent, seat of a safety-valve, the means herein described, or the equivalent thereof, for regulating or adjusting the area of the passage for the escape of steam beyond the bevel, or equivalent, seat, substantially as and for the purpose described." This claim was amended, on suggestions made by the patent-office, to read as granted.

The view taken by the circuit court, in dismissing the bills, was that some valves had been made before 1866, which embodied the same general principle as Richardson's, and were of some value, operating through the expansive power of steam exerted upon an additional chamber outside of the ground joint; and that what Richardson did was to so regulate the action of the chamber outside of the ground joint, by a crack or opening between the lip of the valve and its main body, that the steam would be confined or huddled, when it sought to escape from the chamber, and so the valve would be held up just long enough, and could fall rapidly before too much steam was lost. But the cases went off on the question of infringement, and the circuit court found that while the defendant's valve employed an additional surface to lift the valve as soon as it began to blow, and the pressure was regulated in part by a stricture, it differed from the plaintiff's, in that the additional area was not outside of the ground joint, but inside, and was not acted on independently of the valve itself, but was a part of it, and the escaping steam did not act at all by impact, but wholly by expansion. The conclusion was that, as Richardson was not the first to apply the idea of an additional area or of a stricture, he could not enjoin a valve which resembled his only in adopting such general ideas, and that his claims did not cover a valve having the mode of operation of the defendant's.

Edward H. Ashcroft, as assignee of William Naylor, obtained reissued letters patent of the United States, No. 3,727, dated November 9, 1869, on the surrender of letters patent No. 58,962, issued to said Naylor, October

16, 1866, for an improvement in safety-valves. Ashcroft brought a suit in equity, in the circuit court of the United States for the district of Massachu setts, against the Boston & Lowell Railroad Company, for the infringement of reissue No. 3,727. The infringement consisted in the use of valves constructed according to the patent of 1866 to Richardson. The court dismissed the bill, (5 O. G. 725; 1 Holmes, 366; 1 Ban. & A. 215,) and, on an appeal to this court by the plaintiff, the decree was affirmed. 97 U. S. 189. In view of an English patent, No. 1,038, granted to Charles Beyer, April 25, 1863, it was held by this court that Naylor was not the first person who devised means for using the recoil action of steam to assist in lifting the valve, or who invented the combination, in a spring safety-valve, of an overhanging downward curved lip, with an annular recess surrounding the valve-seat, into which steam is deflected as it issues between the valve and its seat. In speaking of the invention of Richardson, as described in his patent of 1866, this court said: "His invention, as he describes it, consists in increasing the area of the head of the common safety-valve outside of its ground joint, and terminating it in such a way as to form an increased resisting surface, against which the steam escaping from the generator shall act with additional force, after lifting the valve from its seat at the ground joint, and so, by overcoming the rapidly increasing resistance of the spring or scales, will insure the lifting of the valve still higher, thus affording so certain and free a passage for the steam to escape as effectually to prevent the bursting of the boiler or generator, even when the steam is shut off and the damper left open. Safety-valves previously in use were not suited to accomplish what was desired, which was to open for the purpose of relieving the boiler, and then to close again at a pressure as nearly as possible equal to that at which the valve opened. Sufficient appears to show that Richardson so far accomplished that purpose as to invent a valve which would open at the given pressure to which it was adjusted, and relieve the boiler, and then close again when the pressure was reduced about two and one-half pounds to the inch, even when the pressure in the generator was one hundred pounds to the same extent of surface, which made it, in practice, a useful spring safety-valve, as proved by the fact that it went almost immediately intc-general use. * * * When the valve opens, the steam expands and flows into the annular space around the ground joint. Its free escape, which might otherwise be too free, is prevented by a stricture or narrow space formed by the outer edge of the lip and the valve-seat. By these means, the steam escaping from the valve is made to act, by its expansive force, upon an additional area outside of the device, as ordinarily constructed, to assist in raising the valve." On these views, it was held by this court that although important functions, not very dissimilar in the effect produced, were performed by the two valves there in controversy, the means used and the mode of operation were substantially different in material respects.

In the present case, the defendant has introduced in evidence the beforenamed English patents to Ritchie, Webster, and Hartley, and the English patent to William Naylor, No. 1,830, granted July 1, 1863; and also letters patent of the United States, No. 10,243, granted to Henry Waterman, November 15, 1853, and the reissue of the same, No. 2,675, granted to him July 9, 1867. In view of all these patents, and of the state of the art, it appears that Richardson was the first person who described and introduced into use a safety-valve which, while it automatically relieved the pressure of steam in the boiler, did not, in effecting that result, reduce the pressure to such an extent as to make the use of the relieving apparatus practically impossible, because of the expenditure of time and fuel necessary to bring up the steam again to the proper working standard. His valve, while it automatically gives relief before the pressure becomes dangerously great, according to the point at which the valve is set to blow off, operates so as to automatically ar

rest with promptness the reduction of pressure when the boiler is relieved. His patent of 1866 gave a moderate range of pressure, as the result of the proportions there specified, and his patent of 1869 furnished a means of regulating that range of pressure, by a screw-ring, within those narrow limits which are essential in the use of so subtle an agent as steam.

In regard to all the above patents, adduced against Richardson's patent of 1866, it may be generally said, that they never were, in their day, and before the date of that patent, or of Richardson's invention, known or recognized as producing any such result as his apparatus of that patent produces, as above defined. Likenesses in them, in physical structure, to the apparatus of Richardson, in important particulars, may be pointed out, but it is only as the anatomy of a corpse resembles that of the living being. The prior structures never effected the kind of result attained by Richardson's apparatus, because they lacked the thing which gave success. They did not have the retarding stricture which gave the lifting opportunity to the huddled steam, combined with the quick falling of the valve after relief had come. Taught by Richardson and by the use of his apparatus, it is not difficult for skilled mechanics to take the prior structures and so arrange and use them as to produce more or less of the beneficial results first made known by Richardson; but, prior to 1866, though these old patents and their descriptions were accessible, no valve was made producing any such results. Richardson's patent of 1866 states that the addition to the head of the valve terminates in an annular lip, which fits loosely around the valve-seat, and is separated from it by about one sixty-fourth of an inch for an ordinary spring, and a less space for a strong spring, and a greater space for a weak spring, forming an annular chamber, and regulating the escape of the steam; that the steam, when the valve is lifted, passes beyond the valve-seat, and into the annular chamber, and acts against the increased surface of the valvehead, and thus overcomes the increasing resistance of the spring due to its compression, and lifts the valve higher, and the steam escapes freely into the open air, until the pressure is sufficiently reduced, when the spring immediately closes the valve. It is not shown that, before 1866, any known valve produced this result. On the contrary, Richardson testifies that, for about 20 years before 1866, he was acquainted with safety-valves in practical use, by working in the locomotive repair-shops of railroad companies, part of the time as foreman, and as a locomotive engineer, and that he never, before his invention, knew, in practical use or on sale, of any spring loaded safetyvalve capable of opening to relieve the boiler when the working pressure was exceeded, and of automatically closing with a small loss of working pressure. He also says that he was in England, for about four months, in 1873, bringing his valve to the notice of officials in the shops of some of the largest railroad companies, (his valve being one especially useful on locomotive engines on railroads;) that, while he was in England, he found no man who professed to be acquainted with, or to have heard of, a safety-valve which would automatically open and relieve the boiler at a predetermined working pressure, and automatically close when such working pressure had been slightly reduced, or who admitted that such a valve could be made until he had seen Richardson's valve work; that the master mechanics at the shops named did not believe he could make a valve close within 25 pounds of the blowing-off point; that he showed them the working of his valve with no excess beyond working pressure, and with but from 3 to 5 pounds reduction from a pressure of 130 pounds per square inch in the boiler; that he did not hear, in England, of any of the Ritchie, Webster, or Hartley valves, but heard the Naylor valve blow; and that, when it blew, the steam rose several pounds above the point where it commenced to blow, and it did not close promptly, tightly, or suddenly. There is no evidence to contradict, or vary the effect of, this testimony.

Thomas Adams, of Manchester, England, who has spent a life-time in the manufacture and practical working of safety-valves, testifies that the Ritchie and Webster valves have never been in use practically in England, and the Hartley only in two or three cases, when it was a failure; that he himself has made and applied, in England, about 15,000 of Richardson's valves; that, if loaded at 120 pounds per square inch, his valve returns to its seat with a very small loss of pressure; that the Beyer valve, loaded at 120 pounds, reduces the pressure 30 pounds, before returning to its seat; and that Naylor's has been superseded by Richardson's. It appears to have been easy enough to make a safety-valve which would relieve the boiler, but the problem was to make one which, while it opened with increasing power in the steam against the increasing resistance of a spring, would close suddenly and not gradually, by the pressure of the same spring against the steam. This was

a problem of the reconciliation of antagonisms, which so often recurs in mechanics, and without which practically successful results are not attained. What was needed was a narrow stricture, to hold back the escaping steam, and secure its expansive force inside of the lip, and thus aid the direct pressure of the steam from the boiler, in lifting the valve against the increasing tension of the spring, with the result that, after only a sinall, but a sufficient, reduction in the boiler pressure, the compressed spring would, by its very compression, obtain the mastery and close the valve quickly. This problem was solved by Richardson and never before. His patent of 1869 describes the arrangement and operation of the whole apparatus, with the adjustable ring, thus: When the pressure of the steam lifts the valve, the steam acts against the surface of an annular space between the bevel of the valve-seat and the downward-projecting flange of the cap-plate, to assist in holding up the valve against the increasing resistance of the spring. The aperture between the valve and its seat is always greater than that between the flange and the upward-projecting rim, and thus the steam in the annular space assists in holding up the valve till the boiler pressure falls below that at which the valve opened. The difference between the closing pressure and the opening pressure depends on the distance between the flange and the rim. There is a central aperture in the cap, through which the steam escapes when the valve is lifted, which is surrounded by a projecting cylindrical flange, threaded on the outside, to which is fitted a threaded ring, which can be turned up or down, and secured by a set-screw. By this means, the area of the aperture for the escape of steam beyond the valve-seat is adjustable, the space being largest when the ring is down and smallest when the ring is up.

Ritchie's patent, in speaking of his valve, says: "This valve is weighted by a helical spring, i, (shown at Fig. 2,) of sufficient power according to the required pressure of the steam; and, when it is intended to be used as a reserve safety-valve, I place the spring around that part of the stem below the valve, that is to say, within the boiler, as shown at Fig. 2. The advantage of this form of construction of valve over the ordinary valve is as follows: As soon as the pressure of the steam raises the valve from its seat, the flange, h, being exposed to the pressure of the steam, presents an increased surface, which compensates for the increasing resistance of the helical spring, i, until the valve has been raised to a height equal to the area of the steam-way, when it allows the steam or vapor to escape freely." In an article in the Artizan, published in England, in July, 1858, signed by Ritchie, and referring to his patent of 1848, it is said of his valve: "The top area being made double that of the under side or steam-way, such a valve would quickly reduce the pressure in the boiler to half that at which the valve lifted; and so, also, of other proportions. Hence it is chiefly suited for a reserved valve." This shows the existence of the very evil which Richardson remedied. Ritchie's patent and publication say nothing about any stricture.

The evidence in the present case shows, satisfactorily, that valves made ir

conformity with the measurements of the drawing of Ritchie's patent do, in practice, reduce the pressure in the boiler to such an extent, after that pressure is properly relieved, and before they close, as to involve great loss of time and consumption of fuel before the initial pressure is restored. The experimental valves produced by the defendant as structures made according to Ritchie's patent vary from the dimensions of his drawing, and the variations are those which result from the instructions given by Richardson in his patents. Ritchie gives no information how to make a valve work at a predetermined pressure, or how to make it work with a small range of difference between the opening and closing pressures, or how to proportion the strength of the spring and the size of the stricture to each other. The same thing is true of the Webster and the Hartley patents. The Webster patent shows a huddling chamber and a stricture. But the evidence shows that valves made with the proportions shown in the drawings of Webster work with so large a loss of boiler pressure, before closing, as to be practically and economically worthless. Webster's patent describes a means of making the area for the escape of steam adjustable, consisting in adjusting up and down, on a smooth valve-stem, a sliding collar or flange, and fixing it in place by a set-screw. But it does not show the screw-ring of Richardson, with its minute delicacy of adjustment and action. Nothing further need be said as to the Hartley valve or the Beyer valve.

The original patent to Waterman was issued in 1853. His attention had been turned to the subject of safety-valves for locomotive-engines. He invented what is described in that patent, but he testifies that before 1866 he never saw a safety-valve capable of keeping the pressure at a point not above working pressure, and of relieving the boiler with but a small loss of pressure; that his valve would let the steam down about 15 pounds, and was not practical for an ordinary locomotive; and that the Richardson valve, when introduced, went at once into general use. The Waterman valve had a supplemental surface, on which the steam acted to aid in the raising of the valve; and this was shown in the drawing of Waterman's original patent, but the specification did not describe it. Waterman's original patent did not show the use of a spring, and prior to its reissue his valve had not been made with a spring. After Richardson obtained his patent of 1866,-and Waterman knew of Richardson's valve, they combined the interests in their two patents, and the reissue of Waterman's was obtained, with the co-operation of Richardson, he signing, as a witness, the specification of the reissue. That specification, granted in 1867, describes an overhanging part of the valve as increasing its area outside of and beyond the ground joint and a concentric rim or ledge, which directs the steam upward against such overhanging part of the valve, so that the valve is assisted in rising. The specification was drawn in view of Richardson's patent and valve, and for the purpose of making a claim, which was then made, and which was not in Waterman's original patent, to a combination of the concentric rim or ledge with the overhanging part of the valve. The specification states that the valve and its seat are so constructed that the escaping steam will act on an increased area of the valve after it has risen from its seat, and strike the overhanging or *projecting annular surface above and outside of and beyond the ground joint. It also states that a proper modification of the overhanging or projecting annular surface will modify the force of the steam; that if such surface be large the valve will be opened suddenly and discharge so much steam that the pressure in the boiler will be considerably reduced before the valve closes; that such surface may be made so small that but little more than the surplus steam will escape; that the success or efficiency of the valve will depend on a proper proportion between the overhanging annular surface and the concentric rim or ledge, because, if a free discharge of steam between them is allowed, the valve will not be assisted in rising, and if the escape of steam is too small,