also connected, as heretofore, through all the spring and contact points of its switches and through the individual annunciator of the line to the ground." The following illustrated drawing of figure 1 of the patent shows the circuit-testing device:

Fig. 2

Ꮽ

In explanation of the above diagrams, Mr. McBerty, complainant's expert witness, testifies:

"Each springjack is constructed with a switch lever and its contact, and with an additional contact part or line spring. The latter line springs are connected together and with the lines of the substation by uninterrupted continuous conductors. The line annunciator or signal is located in a separate branch, with springs from the line at the head of the system, and traverses the separable contacts of the switch lever and its resting anvil in all the jacks belonging to the line one after the other. When a plug is inserted in any jack of the line it is brought into immediate and uninterrupted connection with the wire to the substation. At the same time it breaks the switch lever from the resting anvil or contact, and so interrupts the branch containing the line annunciator."

The involved claims, 2, 4, and 6, read as follows:

"(2) At a telephone exchange central office, the combination of multiple switchboards with telephone lines each permanently connected to a metallic portion of its switch upon each board, each telephone line being also connected through the contact points of its switches and to ground, and means whereby the circuit of the branch wire of any given line is opened when a connection is made with the line at any board, whereby any two lines may be connected together upon either of the boards without including in their circuits the contact points of either of their switches."

"(4) The combination, with a telephone line provided at each switchboard of a multiple system with a connecting bolt or switch, of a portion of said line connected through an annunciator to ground, and means for breaking said line when a connection is made with the telephone line at either one of its bolts or switches, substantially as and for the purpose specified."

"(6) In a multiple switchboard system, a telephone line provided with a springjack at each switchboard of the system, said springjacks being provided with insulated metallic frames, and said telephone line being connected directly to each of said insulated frames, and also through an annunciator, to ground through the springs and contact points of said springjacks, whereby a connection may be made direct to the telephone line at any board at the same time the portion of said line containing the annunciator is broken, substantially as set forth."

There is no marked difference between claims 2 and 4. In claim 6 the insulated metallic frame arrangement to which the lines are directly connected is specifically mentioned. The testing feature is not included in the claims, and no special form of testing the lines for the purpose of determining whether a line is busy or in use is deemed essential; nor does claim 6 of the patent expressly impose any limitations regarding a special form of springjack. Upon this point the specification says:

"It is evident that this arrangement of circuits may be used with various kinds of switches other than the springjacks having insulated frames as described, and as shown in figure 1."

The patent in question has previously been the subject of attention, and the claims in controversy have been construed by the Circuit Court for the Southern District of Alabama in an action instituted by the complainant against the Home Telephone Company of Mobile. 85 Fed. 649. In that action the court in a carefully considered opinion decided that the invention in suit possessed patentable . merit and that it was a distinct advance in the art of telephony. Claim 6 was held not infringed by the defendant in the Mobile Case; it not being shown that the details of construction of the springjack were

142 F.-49

used by the defendant. In this case the complainant claims, and the evidence supports the claim, as hereinafter stated, that the defendant's insulated springs which are permanently connected to the subscribers' line wire, are the direct equivalent of the insulated metallic frames specified in claim 6; that any two lines may be connected for the purpose of carrying on a conversation on either section of a switchboard without regard to the resistance of the separable contact points; and that at the same time the desired signals and tests may be made is the kernel of the invention. In other words, the act of cutting off the line signal while making connection with the line is of the essence of the improvement and was a new and useful conception. Having stated the object of the patent and the advantages claimed for it, consideration will now be given the various defenses interposed by the answer of the defendant.

The individual defendants, managing officers of the defendant company, deny any participation in the alleged infringing acts mplained of, while the defendant Rochester Telephone Company challenges the validity of the patent, denies infringement, and alleges that the patents are improperly joined in this suit. Was the embodiment of the branch line and metallic portion of each springjack a patentable element? Were such features familiar to the art at the date of the patent in question? Complainant asserts the novelty of the disputed claims, on the ground that each jack, having a metal frame to which the line is connected permanently, is distinct from the separable contacts, while the branch line running though such contacts or switches is retained.

A brief statement of the prior art will enable a clearer understanding of the involved claims. The earlier switchboards in connection with telephony were the so-called dial switchboards having no separable contact points, the single-board class, multiple switchboards without separable switches or contact points, and finally the multiple switchboards having the characteristics of the Scribner patent in suit; that is to say, a multiple switchboard wherein the line circuit traversed through the separable contacts of the springjacks to the annunciator or line signal. It would not be useful to attempt an analysis of the numerous patents introduced in evidence by the defendant to show the antecedent art. Most of such patents were fully considered and analyzed by Judge Toulmin, who reached the conclusion that the prior art was clearly distinguishable from the structure described in the patent under consideration, and also that the patentee had by his invention accomplished a patentable result.

The prior patents chiefly relied on by the defendants to support the denial of invention are the patents to Sabin, Nos. 239,557, dated March 29, 1881, and 249,262, dated November 8, 1881, to Firman, No. 252,576, issued January 17, 1882, and the prior patent, No. 262,701, to C. E. Scribner, August 15, 1882. In the Sabin patents apparatus are shown having contact points wherein the line signal is disconnected by inserting a plug in the springjack. Such patents, it is, confidently asserted, disclosed the alleged novel features of Scribner's invention in suit. It is undeniable that Sabin described a method

which enabled connecting the subscribers' lines unhampered by the resistance of the separable contact points of the circuit; but the switchboards of the Sabin class were not provided with separable. contacts in the switches. It is important to keep in mind that the Scribner patent in suit relates to multiple switchboards of a special class, a class wherein the line signal is opened by the separable contacts induced by the act of the operator in inserting the plug in the springjack. This contention of the complainant finds emphasis in claim 2, wherein it is stated that each telephone line is also connected through the contact points of its switches underground. The Firman patent does not disclose any means by which the troubles in the multiple switchboards could be eliminated, and no such definite. suggestion is contained in the specification as would warrant holding that the Scribner structure in question was obvious or within the ordinary skill of the trained electrician. The defendant lays stress upon the prior Scribner patent, No. 262,701, which relates to a multiple metallic circuit system, and insists that such construction completely anticipates the claims in suit. In this structure the frames of the jacks are connected permanently with the line and the jacks apparently have the same method of cutting off the line annunciator as shown in the patent in suit. The evidence, however, establishes that this apparatus was open to the objection which Scribner's later invention removed. The defendant, in view of such disclosures, contends that the conception and its successful achievement were perfectly obvious, and accordingly involved nothing more than the exercise of mechanical skill. The development of the details and the evolving of the principle by which the resistance of the contact points was eliminated were something more, in my opinion, than a mere modification or alteration of form by which the desired result was attained. That the switches or separable contact points of the springjacks were prevented from successfully closing the line circuit on account of the accumulations of dust and corrosion due to gases, is substantiated by the evidence. The specification in suit admits the state of the art as follows:

"In all these systems [multiple switchboards of the prior art] heretofore used, the contact points of the switches have been included in the circuit of two lines when connected together. My invention is designed to avoid the resistance of these contact points by the use of circuits and apparatus more simple than any heretofore devised, while the operators are enabled to make the usual tests to determine whether any line wanted is already in use at another board."

The defendants' counsel has argued with much earnestness against this conclusion, but I am clearly of opinion that Scribner, by modify ing and altering the structure of his earlier patent, made a substantial and meritorious step forward in the art. It is true, as already stated, the Scribner patent, No. 262,701 related to a metallic circuit system, and, although to change to a grounded system may not have involved patentability, still I am persuaded by the evidence that the inefficiencies of the talking circuit would not have been removed by a simple substitution of grounding connections, or by running to ground the wire, a. As said in Western Electric Co. v. Home Telephone Co., supra:

"It does not seem to admit of doubt that this patent accomplishes a new result, namely, the direct connection of two subscribers' lines through the usual plugs and cords, at the same time cutting out of the talking circuit thus formed all of the separable contacts belonging to such lines, and cutting out the conductors leading to the individual annunciators. The instrumentalities employed to accomplish this result are not, individually, new instrumentalities, but they are brought together in a new relation, combination or organization, and thereby produce this advance in the art of telephony, * and the advantages it affords in the actual use of telephones, by simplifying the apparatus in telephone exchanges, by improving the tone and efficiency of talking circuits, through the elimination of objectionable resistance to the low current employed in such circuits."

This conclusion on practically the same evidence as here is persuasive, and I am satisfied of its correctness. The additional evidence introduced by the defendant is thought insufficient to warrant holding that the patent in suit is anticipated. As to infringement. The Webster diagrams in evidence, according to complainant's expert witnesses, indicate inter alia the use by the defendant in its earlier and later apparatus of the combination of elements described in the claims in controversy. In the switchboard of the defendant company the line circuit in connection with the longer line springs of each jack to the branch line leads from the contact points of the first jack to another. The plug, as illustrated in Webster's diagram No. 2, after lifting the same from the contact anvil, is put into the springjack and is closely held by the longer springs thereof. Upon the removal of the plug from the contact anvil the branch wire running to the line signal and ground battery is cut off, while the sleeve of the plug upon being pushed into the desired line springs operates to connect the line. Each line or circuit running into the central office is connected permanently to the insulated metallic frame of its springjack upon each board or section and also through the contact points of its switches, and thus to the ground. By such means, without fully stating the details, an uninterrupted circuit of separable contacts is provided to the defendant's structure. The evidence relating to infringement of claims 2 and 4 is persuasive, and the substitution of the ground system for the metallic system as shown in the modified structure is unimportant. The form of construction of the defendant's line springs is concededly different from complainant's metallic portion of the switch, but the patentee did not limit himself to a particular form or style of insulated metallic frames to be used in connection with the jacks. The springjacks used by the defendant company as to results attained, notwithstanding the conflicting testimony on this point, were practically the same as complainant's. In view of the scope to which the patent is fairly entitled, as evidenced by claim 6, the equivalency of the two elements is thought beyond serious question. The case comes within the doctrine enunciated by the Supreme Court in Machine Co. v. Murphy, 97 U. S. 120, 24 L. Ed. 935, and by the Circuit Court of Appeals, Eighth Circuit, in Kinloch Tel. Co. v. Western Electric Co., 113 Fed. 652, 658, 51 C. C. A. 362, where it is said:

"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