Brake Beam Co., 106 Fed. 693, 711, 45 C. C. A. 544, 562; Watch Co. v. Robbins, 64 Fed. 384, 396, 12 C. C. A. 174, 178, 22 U. S. App. 601, 634; New Departure Bell Co. v. Bevin Bros. Mfg. Co. (C. C.) 64 Fed. 859.

In the light of these principles of law, how can the contention of the appellants be sustained? It is conceded that the wire connections, the plates of the appellants' combination, and their silk dielectric are the mechanical equivalents of the like connections, the plates, and the slotted dielectric of the patented device. It is conceded that the appellants' combination performs the same function discharged by that of the complainant. The only question is whether the means used by the appellants to produce the metallic conducting link between the plates are the mechanical equivalents of the plug of easily-fusible material adopted by White. The principle on which White's device for the production of this conducting link is constructed is to secure the material for it in the face of one of the plates until it is released by the heat of the plate after an arc has been formed between the plates. The device of the appellants is constructed upon the same principle. The shot are held in holes in the faces of the plates until the heat produced by the arc between them melts the wax and releases the leaden balls. The mode of operation whereby White forms the metallic conducting link between the plates is that the heat of the plates, resulting from the continual maintenance of an arc between them, melts his fusible material in the upper plate so that it runs down between the plates and forms the conducting link. The mode of operation of appellants' device is that the heat of the plates, resulting from the continued maintenance of an arc between them, melts the wax which holds the shot in their holes, and they run down between the plates and form the conducting link. Thus it will be seen that the two devices are constructed upon the same principle that they have the same mode of operation, that they accomplish the same result, and that the means whereby they reach it are mere mechanical substitutes for each other. When the fact was discovered and illustrated by the fusible plug in the carbon plate of White, that material held in the face of a plate until the latter was heated by a persistent arc so that it would melt and release the plug, prevented the formation of the metal conducting link between the plates until, and produced it at, the proper time to discharge the function of the patented device, a shot or a piece of insoluble conducting material of any kind held in the face of a plate by wax, or any other fusible material, so that it would be prevented from making the metal conducting link until the proper time, and would then be released and form the link by the melting of the wax or the other material, so that the function of the device would be properly discharged, became the plain mechanical equivalent of White's fusible plug, and was, in legal effect, the same thing as that plug, because it was an evident mechanical substitute for it, used for the same purpose, and accomplishing the same result. The result is that White's claim of his device was, within the meaning of the patent law, a claim of the device of the appellants as much as of his own device, and he did not surrender or abandon to the public that combination, or any similar mechanical equivalent of his invention.

An attempt is made to escape from this conclusion under the rule that, if the element substituted for the one withdrawn has been discovered since the date of the patent, it cannot be said to be its mechanical equivalent. Gould v. Rees, 15 Wall. 187, 193, 21 L. Ed. 39: Counsel for the appellants says that the shot and the wax have been discovered since the patent to White, and have been secured by a subsequent patent to Frank B. Cook, No. 658,976, dated October 2, 1900. It is true that such a patent has been issued; but it is too plain for argument or serious consideration that there was neither discovery nor invention in perceiving or applying to the device of the complainant the fact that an insoluble metal secured by wax or other fusible material was the mechanical equivalent of, performed the same function and worked the same result as, the fusible plug of White, and could be effectually used as its substitute. The shot and wax were not, therefore, newly discovered elements, but constituted a mere mechanical substitute for the element which White described and claimed.

The second position of counsel for the appellants is that they do not infringe, because, when attention is paid to the parts which really do the work, their device does not accomplish its result in the same way as does that of the complainant. Machine Co. v. Murphy, 97 U. S. 120, 125, 24 L. Ed. 935, Cahoon v. Ring, Fed. Cas. No. 2,292, 1 Cliff. 592. It is contended that in the combination of White the fusible material forms the conducting link between the plates, while in the device of the appellants the fusible material (the wax) does nothing at all, but is simply used to hold the shot in place while the machine is constructed. There is testimony in the record in support of this statement of the purpose and use of the wax, but it is not convincing evidence. The patent to Cook, in practical accord with the description in which the device of the appellants is constructed, shows clearly that the purpose of the wax was not to hold the leaden balls until the combination was made, but to withhold them after its construction so that they would not close the circuit until the wax was melted into a liquid by means of the heat created by the abnormal discharge of the current across the dielectric between the plates, and then to permit them to make the conducting link and close the circuit as in the combination of White. One witness testifies that in practice he thinks the burning away of the silk occurs before the melting of the wax. The court below reached the conclusion that the testimony of this witness was the truth; that the silk dielectric is sometimes burned away at a point which would permit the loose balls to come together, although the heat. is not sufficient to melt the wax. In view of the evidence to which reference has been made, this finding of fact ought not to be disturbed. The patent to Cook is of much greater value as evidence of the purpose and operation of the wax than the testimony of interested witnesses after this litigation had commenced. We accordingly adhere to the view of the court below that the purpose and effect of the wax was to hold the conducting material until the heat generated by the arc melted the wax and released the shot, so that they would run down and form the conducting link between the plates. In this state of the case, the only difference in the operation of the two devices to form this conducting link is that in the one the fusible material, when it

melts, not only releases the material which forms the conducting link, but itself becomes that link, while in the other the only function of the fusible material is to hold until it melts, and then to release the shot which become the conducting link between the plates. This, however, is an immaterial difference. It is not of the essence of the invention or of its operation. The essence of that part of this invention which relates to the fusible plug-the mode of operation which distinguishes it from all other devices-is the holding of a conducting material out of the circuit in one of the plates by means of a fusible material until an arc heats the plate and melts the fusible material so that it releases the conductor, and causes it to form the link between the plates. This mode of operation-this distinguishing characteristic of the inventionthe appellants have completely appropriated. Their device holds the conducting material out of circuit in the same way that White's does, -by a fusible material. It releases it in the same way that White's device does, by the melting of the fusible material. And it forms the conducting link between the plates in the same way that the combination of White does,-by permitting the conducting material to run down between the plates and in contact with them at the appropriate time. The two devices were constructed for the same purpose. They have the same mode of operation, and they accomplish the same result in the same way, by equivalent mechanical means. The appellants cannot escape liability for the appropriation of the entire essence of this invention by the slight change they have made in a single element of the combination which embodies it.

This conclusion has not been reached without a careful consideration of all that has been said and written concerning the effect of the silk dielectric, its partial burning, and its carbonization in the operation of the device of the appellants. But inasmuch as the complainant's patent clearly covers a potential discharger using a silk dielectric in the place of the slotted mica partition, our conclusion is that the discussion of the operation and effect of the silk dielectric is not material to the determination of the issue presented in this case, and for that reason it has been pretermitted. This case stands as it would have stood if the device described in the patent had contained a silk dielectric in the place of the slotted mica partition. The appellants can reap no advantage and can escape no liability on account of the peculiarities of the operation of the silk which they have substituted for the mica partition of White.

The decree below is sustained by the evidence, is warranted by the law, is equitable and just, and it is affirmed.

(113 Fed. 659.)

KINLOCH TEL. CO. et al. v. WESTERN ELECTRIC CO.

(Circuit Court of Appeals, Eighth Circuit. February 17, 1902.)

No. 1,637.

1. PATENTS-COMBINATION OF OLD ELEMENTS.

A new combination of old elements, whereby an old result is attained in a more facile, economical, and efficient way, may be protected by a patent.

2. SAME-INVENTION-IMMEDIATE AND GENERAL USE EVIDENCE OF.

Where the question of novelty is fairly open for consideration under the law, the fact that a patented device or combination has displaced others which had previously been used to perform its function, and has gone into immediate and general use, is pregnant and persuasive evidence that it involves invention.

3. SAME LETTERS PATENT No. 330,067 VALID.

Letters patent No. 330,067, dated November 10, 1885, to John A. Seely, for an improvement in grouping spring jacks and annunciators for mul tiple switchboards, are not void for want of novelty in the device, or of invention in its production, and they are infringed by the divisional system of the Kinloch Telephone Company.

4. SAME-INDEPENDENT INVENTIONS PATENTABLE WHERE ADVANCE IN ART GRADUAL.

Where the advance toward the desideratum is gradual, and several inventors form different combinations which accomplish the desired result with varying degrees of operative success, each is entitled to his own combination, so long as it differs from those of his competitors and does not include theirs.

(Syllabus by the Court.)

Appeal from the Circuit Court of the United States for the Eastern District of Missouri

R. S. Taylor, for appellants.

Frederick P. Fish and George P. Barton, for appellee.

Before CALDWELL, SANBORN, and THAYER, Circuit Judges.

SANBORN, Circuit Judge. The circuit court rendered a decree in favor of the Western Electric Company, the complainant in that court, to the effect that the defendants, the Kinloch Telephone Company and Samuel M. Kennard, had infringed the first three claims of letters patent No. 330,067 issued to John A. Seely on November 10, 1885, for an "improvement in grouping spring jacks and annunciators for multiple switchboards," and perpetually enjoined them from using the invention described in those claims. The defendants have appealed from this decree, and they insist that it is erroneous, on the usual grounds, that the combination described in the patent was the product of mechanical skill, and not the result of the exercise of the inventive faculty, and that they have not used the combination. three claims of the patent involved read in this way:

The

“(1) In a multiple switchboard system in which the individual annunciators are distributed in groups upon the different boards, switches for all the lines on each of the boards, and, in addition thereto, sets or groups of switches

51 C.C.A.-24

on the different boards corresponding to the different groups of individual annunciators, each group of annunciators and its corresponding group of switches being placed relatively to each other in the same position on each of the boards, whereby the manner of answering the subscribers is made uniform upon all the boards. (2) In a multiple switchboard system, a springjack switch on each board for each line, and additional spring-jack switches, one in each line, for the initial connection, said additional spring-jack switches being distributed on the different boards in uniform groups, and the individual annunciators of the different lines arranged in corresponding groups, substantially as and for the purpose specified. (3) In a multiple switchboard system, a spring-jack switch on each board for each line, and additional spring-jack switches, one in each line, for the initial connection, said additional spring-jack switches being distributed on the different boards in uniform groups arranged in lines across the boards, and the individual annunciators of the different lines arranged in corresponding groups, substantially as and for the purpose specified."

The improvement of Seely described in these claims relates entirely to the placing and grouping of switches and annunciators in a multiple switchboard system. He describes in his claims two classes of switches which in the operation of his combination perform different functions. A switch is any device by which one line may be electrically connected with another. The form in common use switchboards in the telephone exchanges consists of a socket set in the switchboard containing the terminals of the two sides of the subscribers' circuit, and this is used by means of a plug which contains the terminals of the two wires that are attached to it in a cord. The insertion of the plug in the socket makes the electrical connection between the subscriber's line and the wires attached to the plug, and these wires usually lead to another similar plug or to the telephone of the operator. If they lead to another plug, electrical connection may be made between the lines of two subscribers by inserting these plugs in the respective switches of the subscribers upon the switchboard. These sockets set in the switchboard through which the subscribers communicate with each other are called "switches" in Seely's patent, but they are also called "jacks," "spring-jacks," "spring-jack switches," and "line jacks." In this opinion they will be termed "line jacks." They are the "switches for all the lines on each of the boards" specified in Seely's first claim. The "groups of switches on the different boards corresponding to the different groups of individual annunciators" will be called answering jacks, to distinguish them from the line jacks, and because their function is to enable the operator to answer the calls of the subscribers and to learn their wants by plugging into them instead of into the line jacks, and thus electrically connecting her telephone with the wires of the subscribers when their annunciators announce their calls. When Seely made his invention the annunciator commonly used was a shutter hinged at its lower edge, which dropped and disclosed the subscriber's number when he took his telephone from its hook or otherwise actuated thecurrent so as to release the catch which held the shutter in place. The multiple switchboard upon which Seely made his improvement was the switchboard divided into sections usually by perpendicular lines described in the patent to Firman of January 17, 1882. After Seely had placed his improvement upon it each section of this board. contained all the line jacks of all the subscribers served by the entire