ents of defendants showing the state of the prior art, the fact that defendants are manufacturing a different box under their subsequent patent, and the admission of complainant's expert that Marburg's invention consisted "of a judicious selection of a certain location for the cuts," leave the question of infringement in such doubt that the motion for a preliminary injunction must be denied.

The chief contention of complainant's counsel in his briefs and argument was that the individual defendants and defendant corporation were estopped to deny the validity of the Marburg patent, because said individuals sold said patent to complainant, organized the defendant corporation, own much more than a majority of its capital stock, and control its business. The conclusion reached dispenses with the necessity of considering either the question of patentable novelty or of estoppel. The motion is denied.

CHILDS v. JOSEPH STELWAGON CO.

(Circuit Court, E. D. Pennsylvania. January 12, 1900.)

No. 5.

PATENTS-INFringement—Roofing Material.

The Childs patent, No. 429,885, for an improved roofing material, consisting of an upper and lower layer of paper or other fabric, between which is interposed a layer of bituminous or other similar material, construed, and held not anticipated; also held infringed.

This was a suit in equity for infringement of a patent. On final hearing.

Charles G. Coe, for complainant.

E. Hayward Fairbanks and William C. Strawbridge, for respondent.

MCPHERSON, District Judge. This suit is brought to restrain the alleged infringement of letters patent No. 429,885, issued to the plaintiff in June, 1890. The subject of the patent is an improved roofing material, and the claim is as follows:

"The fabric above described, consisting of an upper and lower layer of paper or other fabric, between which is interposed a layer of bituminous or other similar material, such material being unwoven, held in place by cords, ribbons, or other filamentous material of a thickness uniformly equal to that of the central layer, as set forth."

In view of the prior state of the art, some reference to which is found in the specification of the patent, it is clear that the claim is to be construed narrowly. The specification and the history of the application make it plain that the patent is to be confined to a roofing material in which the interposed bituminous layer is of a "definite" thickness, and the cords, ribbons, or other filamentous material are "precisely" as thick as the layer. But even words so positive as are here used must have a reasonable interpretation, especially when it is considered that, according to the usual method of manufacture, the thickness of the layer would always be expressed in a very small fraction of an inch. The layer of the patent is little

more than a film, but, as no greater thickness is needed, none is used. When, therefore, it appears that the difference in thickness between the bituminous layer in the fabrics manufactured respectively by the plaintiff and the defendant is so slight that it can scarcely be detected by the aid of a strong magnifying glass, and that a delicate instrument of precision is needed to decide whether the wire used by the defendant differs in diameter from the wire used by the plaintiff, it seems to me that a point has been reached when the minute differences that may exist can be fairly disregarded, and the court may justly say that both parties are using the same "definite" thickness of bituminous material and the same size of wire, and that the wire in each case is "precisely" of the same thickness as the layer. Is, then, the result produced by the use of this material and the manner of producing the result the same in both instances? I think the question must be answered in the affirmative. There is the usual conflict of expert opinion in the testimony, resulting in the usual doubt in the mind of the court whether such a thing as scientific truth can be said to exist when a question of infringement is being fought out. So far as I can judge, however, the defendant's theory is not sound. I think there must be a layer-although, no doubt, it is a thin layer-of bituminous material between the inclosing sheets of felt in the defendant's fabric; for the sheets are already saturated with similar material before the liquid bitumen is applied, and can absorb little, if any, more. The bituminous material must, therefore, exist as a separate and definite layer between the inclosing sheets. Neither are the wires imbedded in these sheets, but are imbedded in the bituminous layer,-as, indeed, the defendant expressly declares to the public in some of its advertisements, -and the wires perform in the layer the same pocketing function that is performed by the wires in the plaintiff's fabric. This is true also of the sinuous wire used by the defendant. Some effort was made to treat the wires used by the defendant as a coherent structure, and to class it as a "gauze," or a "woven" fabric, because the sinuous wire crosses two other wires once or twice in 8 feet, and extends upward and downward far enough to reach sometimes-but not to cross-the upper and lower wires of the four that extend longitudinally in the defendant's fabric. I do not think the effort was serious, but, in any event, it was not successful. The direction of the sinuous wire is, on the whole, longitudinal, as is the direction of the other wires; and, so far as I can see, it performs the same function as the others. I do not regard these five wires as a gauze, or a woven fabric or structure, in any proper sense of these words. I see no escape from the conclusion that the defendant's fabric infringes the patent in suit.

Without discussing in detail the patents that are declared to anticipate the plaintiff's invention, I may say in a word that I have examined and considered them all, without being able to sustain the defendant's position upon this point. A decree may be entered for an injunction and the usual accounting.

NATIONAL CASH-REGISTER CO. v. NAVY CASH-REGISTER CO. (Circuit Court, N. D. Illinois, N. D. January 6, 1900.)

No. 25,351.

PATENTS EVIDENCE OF ASSIGNMENT-PATENT-OFFICE RECORDS.

Certified copies of patent-office records of assignments are not primary evidence of such assignments, and are only admissible to prove title to a patent where proper foundation is laid by showing the existence of the original instruments, and that they are lost or destroyed, or that it is out of complainant's power to produce them.

This is a suit in equity for infringement of a patent. On motion for preliminary injunction.

Edward Rector, for complainant.

Offield, Towle & Linthicum and Thos. W. Flynn, for defendant.

KOHLSAAT, District Judge. Defendant insists that complainant's title is not properly established in this case, as no proper foundation was laid for the introduction of certified copies of the record of assignment in the patent office. In this I concur. My views of this question coincide with the opinions of the circuit courts of appeals of the First and Second circuits, as stated in Paine v. Trask, 5 C. C. A. 497, 56 Fed. 233, and City of New York v. American Cable Ry. Co., 9 C. C. A. 336, 60 Fed. 1016, respectively, and also with the dissenting opinion of Judge Woods in the Crane Elevator Case, 22 C. C. A. 549, 76 Fed. 767. Certified copies of patent-office records of assignments are not made evidence by any United States statute, and, if competent at all, must conform to the rules relating to primary and secondary evidence, and are only admissible when proper grounds are laid; i. e. upon showing the former existence of the original instruments of assignment, and the fact that they are lost, or that it is out of complainant's power to obtain the same for introduction in evidence, or that no better evidence is in existence. Even where copies of the records of deeds are by statute made evidence in this state, it is a requisite that good reason be shown for the nonproduction of the original before the certified copy is admissible. I know of no reason why the best evidence should not be required in patent matters whenever it is possible to obtain the same, nor any rule which dispenses in patent litigation with the safeguards placed around the reception of secondary evidence in other suits. Until competent proof of complainant's title is shown, the court cannot entertain the motion for a preliminary injunction herein, and therefore I deem it unnecessary to pass upon the other questions involved. The motion for a preliminary injunction is denied, with leave to renew application.

NOONAN v. CHESTER PARK ATHLETIC CLUB CO. et al.

(Circuit Court of Appeals, Sixth Circuit. January 2, 1900.),

No. 668.

1. PATENTS-SUIT BY ASSIGNEE AGAINST PATENTEE FOR INFRINGEMENT-EXTENT OF ESTOPPEL BY ASSIGNMENT.

The estoppel created by the assignment of a patent does not prevent the assignor from denying infringement, and, in a suit against him therefor, the court will not assume in favor of the assignee anything more than that the invention presented a sufficient degree of utility and novelty to justify the issuance of the patent, and will apply to such patent the same rule of construction, with such limitation, which would be applicable between the patentee and a stranger.

2. SAME CONSTRUCTION OF CLAIMS-EQUIVALENTS.

Where the validity of a patent rests entirely upon the novelty of the specific combination of means to carry the idea of the inventor into practical execution, the means themselves being old, the range of equivalents allowable to the combination must be so narrowed as to include nothing which is not substantially identical with the means used by the patentee. The use of other known means, though equivalent in function, does not constitute infringement.

3. Same-EquIVALENT COMBINATIONS.

Where the devise shown by a patent consists of a combination of old elements, it is entitled only to a very limited application of the doctrine of equivalents, and is not infringed by combination of different elements, also old, to accomplish the same purpose, unless the substitutions are merely colorable.

4. SAME-INFRINGEMENT-PLEASURE RAILWAYS.

The Thompson patents, No. 332,762, for improvements in gravity switchback railways, and No. 367,252, for improvements in elevated gravity and cable railroads, the latter being for an improvement on the structure of the former, which consists mainly in adding a cable as a motive power for carrying the cars up the ascending grades, with a device for automatically releasing them when they start upon a descending grade, when construed and limited as required by the prior art, are neither of them infringed by the electric pleasure railway of the Lilley patent, No. 549,700.

Appeal from the Circuit Court of the United States for the Southern District of Ohio.

This is a bill to restrain the infringement of patents No. 332,762 and No. 367,252, both issued to La Marcus A. Thompson. The first is for certain improvements in gravity switch-back railways, and the second is for improvements in elevated gravity and cable railroads. The complainant, Noonan, is the assignee of Thompson of the exclusive right under said patents of a limited territory, which includes the county of Hamilton, in the state of Ohio. The defendants are the Chester Park Athletic Club Company, a corporation of the state of Ohio, La Marcus A. Thompson, the patentee under whom complainant claims, C. M. Lawson, Luke Lilley, and John Devere, all of whom are stockholders and managing officers of the defendant corporation. The defendants denied infringement, and upon this issue the circuit court dismissed the bill, and the complainant appealed.

George J. Murray, for appellant.

W. W. Wood, E. E. Wood, and Thomas L. Pogue, for appellees. Before TAFT, LURTON, and DAY, Circuit Judges.

LURTON, Circuit Judge, after making the foregoing statement of facts, delivered the opinion of the court.

1. The evidence by which it is sought to connect the defendants Lilley and Devere with the purchase by complainant of an interest under the Thompson patents involved, for the purpose of estopping them, and through them the corporation of which they are members, is insufficient to in any way affect the disposition of any question involved in the case.

2. Thompson, the inventor and assignor of complainant, is the president of the defendant corporation, and is undoubtedly affected by the estoppel growing out of his assignment. Without deciding, we shall, for the purposes of this case, assume that the corporation is affected by the estoppel which prevents Thompson from denying the validity of the patents which he has assigned, and apply to it the same principles which would affect him if he were the sole defendant. It seems to be well settled that the assignor of a patent is estopped from saying his patent is void for want of novelty or utility, or because anticipated by prior inventions. But this estoppel, for manifest reasons, does not prevent him from denying infringement. To deter mine such an issue, it is admissible to show the state of the art involved, that the court may see what the thing was which was assigned, and thus determine the primary or secondary character of the patent assigned, and the extent to which the doctrine of equivalents may be invoked against an infringer. The court will not assume against an assignor, and in favor of his assignee, anything more than that the invention presented a sufficient degree of utility and novelty to justify the issuance of the patent assigned, and will apply to the patent the same rule of construction, with this limitation, which would be applicable between the patentee and a stranger. Babcock v. Clarkson, 11 C. C. A. 351, 63 Fed. 607; Ball & Socket Fastener Co. v. Ball Glove-Fastening Co., 7 C. C. A. 498, 58 Fed. 818; Cash-Carrier Co. v. Martin, 14 C. C. A. 642, 67 Fed. 786; Chambers v. Crichley, 33 Beav. 374; Construction Co. v. Stormberg (C. C.) 66 Fed. 550; Clark v. Adie, 2 App. Cas. 423, 426. This was the rule applied by the court below, and is the principal ground of objection to the decree finding that the assigned patents, when limited by the previous state of the art, had not been infringed.

3. The defendant Thompson, in 1897, constructed for the complain ant an elevated gravity and cable railway, according to the claims of his patent No. 367,252, and assigned to him the exclusive right under that patent, as well as under patent No. 332,762, within three counties in the state of Kentucky and two in the state of Ohio. Subsequently, Thompson, with others, organized the Chester Park Athletic Association, and sought to obtain from the complainant a license to construct and operate a similar railway upon the property of the association which was within the territory assigned to complainant. The parties could not agree upon terms, and thereupon a railway of similar general character and uses was constructed under plans devised by the defendant Luke Lilley, who subsequently applied for and obtained a patent for his structure, being patent No. 549,700, of March 30, 1897. The contention is that this "Lilley Electric Pleasure Railway," as it is styled in the patent to Lilley, infringes the com