as a disclosure of the broad invention of such a resistance insertion device.

The Pope patent shows such a device applied to railway signal apparatus, and the Timmins & Currie patent employs it in a switch controlling an electric lighting circuit. Other patents, such as Pope patent and Cummings patent, both of 1884, show a further development of the Snith pioneer invention. But none of these patents show this invention applied to the solenoid form of electromagnet, to which the patent in suit is limited, and it does not appear that the ordinary electro-magnet could be used in the combination of the patent in suit.

The prior Whittingham patent was not pressed by counsel for defendant. While it was of the solenoid type, it was not provided with any appliances or devices for accomplishing the objects of the device of the patent in suit. The solenoid required was one which should be capable of discharging the two functions of providing for the strong pull with full power and the light grip with economy of power. The device in suit provided such a solenoid, and combined with it the principle of the Smith switch, brought into the circuit of the solenoid when its core neared the top of its movement, thus practically supplying two solenoids, more efficient because of the light grip caused by the high resistance lamp, and with resultant protection of solenoid windings, and simplicity and economy in its construction and operation.

In the disposition of this question of invention, it may be assumed that the patentee's sole contribution consisted in the conception that it was possible to select from a somewhat remote, but allied, branch of the prior art well-known tools, which were capable of accomplishing these functions, and of so combining and adapting them as to secure new and useful results. It is forcibly argued that the conception of this possibility and its practical accomplishment was obvious, and involved the exercise of mere mechanical skill and development. But when it appears that Smith and Pope in 1873, and Timmins & Currie in 1888, and Whittingham in 1889, had disclosed to the art the devices now relied on to defeat the claim, and that with the manifest and urgent call for a device possessing the advantages admittedly possessed by the patented device, it did not occur to any one till 1892 to suggest such a combination, and that the progress of the art had stopped until the patentee brought out his apparatus, we have presented one of the strongest arguments for, and one of the most decisive tests of, invention.

This invention consisted in the conception of a possibility of changing power for a strong pull into power for a light grip, and of securing these two functions in one solenoid by the introduction of the high resistance, with resultant cheaper construction and operation and greater efficiency. It was realized by a novel combination of old elements, mutually co-operating to effect the same result by means of the double function of the solenoid core operating, first on the low resistance rheostat, and then on the high resistance lamp, in

connection with the co-operation of the cap, which produced new and useful results possessing advantages which had never been previously accomplished.

Defendant's device is shown by the following copy of a photograph:

A is the solenoid; B the lamp; D the iron cap; J, E, K, the device for short-circuiting the lamp; C the solenoid core. F is the pin on the contact arm, which engages with the switch, E, to break the short circuit of the lamp, B.

This construction comprises a combination of the motor of the Blades patent, No. 453,032, owned by defendant, with a switch of the type shown in the Smith and Pope patents of 1873. The Blades patent covered automatic switch mechanism; but, although later than the first Whittingham patent, it failed to show a solenoid or any improvement in the line of invention here under consideration upon the earlier Whittingham apparatus. Although the switch is, electrically connected with the top of the solenoid, it is not mounted therein or arranged with a pin and spring as in the patent in suit. The switch short-circuiting device, therefore, is the old one described in connection with the Smith patent, where the switch is operated by means of a pin on the contact arm and the resistance thus inserted as the contact arm approaches the end of its travel.

But the patentee, in the patent in suit, did not confine himself to means described for short-circuiting. Thus, he says:

"It will also be readily seen that the peculiar method described of shortcircuiting the conductor of high resistance is a simple mechanism which may be varied at will. This device is a simple and convenient one for automatically throwing the conductor of high resistance into or out of circuit. I therefore do not confine myself to the structure of these details, but employ them only as means to accomplish the mechanical portions of my combination, which may be varied without affecting or changing the real operation of my invention."

This statement is abundantly justified by the state of the art. The Smith short-circuiting device was well known and in common use, and the patent had expired; but the patentee, recognizing that his invention resided, not in the form of switch, "a simple mechanism which may be varied at will," but in the novel combination and adaptation with new and better results, merely states his preferred form as the one best adapted to secure the results to be accomplished.

It is impossible to determine whether the defendant's cap discharges the important function claimed for the iron cap of the patent in suit, namely, the contact-breaking rapid motion of the core at the end of its upward travel. Its cap is provided with a conically recessed plug, so extending into the solenoid that the upper end of the core, being of a corresponding conical shape, coacts with it; the result being a uniform pull during the whole range of travel of the core. The quick movement at the end of the stroke is secured in defendant's device by a form of dash pot, not necessary to be explained here, wherein the retarding effect is removed as the core approaches the limit of its travel. The experts support their conflicting claims by statements and by experiments, the effect of which cannot be satisfactorily proved. But in view of the specific statement of the patent as to the construction and function of the cap, and of the limitations of the prior art, it is thought that the patentee should be confined to the claims covering the precise details of such

construction, and that said claims cannot be broadened to include the defendant's device.

The conclusion reached is that claim 6, for an iron cap upon the solenoid, and claim 7, for such cap with a specific form of conducting governor, and claim 8, for such a cap and two terminals mounted upon the top of the solenoid, are not infringed.

The question as to the infringement of the other claims, as already shown, depends upon whether complainant's invention was of such a character as to permit him to cover the construction which includes the Smith resistance insertion device. In this aspect, we may accept defendant's argument of the question of infringement, and treat the Smith device as a well-known electrical tool which any one had the right to adopt. That it remained ready at hand for nearly 20 years, and that Blades and Whittingham and other inventors failed to see its adaptability to their apparatus, is most persuasive evidence of invention, in connection with the other evidence discussed. Therefore, as the patentee was the first to discover the new and undeveloped possibilities of adaptation, combination, and result, and merely illustrated his preferred form, and stated it, as above, he should not be deprived of the benefit of his invention by reason of the existence of this obvious and well-known equivalent. The patent responds to the following tests of invention: It is novel, the first apparatus which "controlled definitely two independent resistances in two independent circuits at definitely co-ordinated intervals of time." It is of great utility. With other inventors in the field, all striving for the same end, the patentee was the first to conceive the possibilities of such a combination. The question of law propounded must be answered, therefore, in the affirmative. Claims 4 and 5 are infringed. Claims 6, 7, and 8 are not infringed. Let a decree be entered for an injunction and an accounting in accordance with this opinion, and for complainant to recover onehalf its costs.

B. F. AVERY & SONS v. J. I. CASE PLOW WORKS.

(Circuit Court, E. D. Wisconsin. July 17, 1905.)

1. PATENTS-CONSTRUCTION OF CLAIMS-EFFECT OF FORMULA "SUBSTANTIALLY AS DESCRIBED."

Where a patent contains specific claims in which certain features described in the specification are expressly claimed, and also broad claims from which such features are omitted, they cannot be read into the broad claims because of the closing formula "substantially as described," for the purpose of narrowing such claims to avoid anticipation.

[Ed. Note. For cases in point, see vol. 38, Cent. Dig. Patents, § 241.]

2. SAME-INFRINGEMENT.

Where a patentee in a claim for a combination specifies any element as entering into the combination, he makes such element material to the combination, and it cannot be held immaterial by the court for the purpose of finding infringement.

[Ed. Note. For cases in point, see vol. 38, Cent. Dig. Patents, § 253.]

3. SAME-EQUIVALENTS-APPLICATION OF DOCTRINE TO IMPROVEMENT PATENT. In applying the doctrine of equivalents, the courts discriminate in favor of a primary patent, and a narrower rule is applied to a patent which is merely for improvements upon an old mechanism, in which case the doctrine is applied only to changes which are palpably colorable.

[Ed. Note.-For cases in point, see vol. 38, Cent. Dig. Patents, §§ 374, 379.]

4. SAME-INFRINGEMENT-PLOWS.

.

The Avery patent, No. 650,771, for a double moldboard plow, claims 2 to 6, inclusive, which are broad claims, are void for anticipation in the prior art; claims 7 and 8, which cover a specific combination of old elements, including "brace rods rigidly secured to the moldboard," and attached at the other end to the runner, which perform the function of bracing and strengthening the moldboard, disclose invention, and are valid, but are limited by such specified elements, and are not infringed by a construction in which the braces from the runner are not attached to the moldboard, and do not, therefore, perform such function.

In Equity. Suit for infringement of letters patent No. 650,771 for a plow, granted to George C. Avery May 29, 1900. On final hearing.

This is an action in equity, predicated upon alleged infringement of letters patent No. 650,771 for an improvement in the "double-moldboard" or "middleburster" plows. The bill is in the usual form. The answer denies that the patented structure discloses any patentable invention in view of the state of the art; avers that complainants' invention had been anticipated by United States letters patent No. 410,218, issued to Ira W. Sylvester September 3, 1889. Infringement is also specifically denied.

The original verified application of the patentee contained four claims, which are found at pages 89 and 90, defendant's record. The second claim was rejected on the Ward patent No. 604,814. (Defendant's record, page 178.) Thereupon the second claim was canceled, and the attorneys for the patentee reconstructed the application, and substituted the present claims Nos. 2, 3. 4, 5, and 6 in place of the canceled claim. Original claims 3 and 4 became 7 and 8 in the amended application. Thereupon the amended claims from 2 to 6, inclusive, were again rejected, on Billups' patent,, No. 123,858, and Sylvester's patent, No. 410,218. Reconsideration was asked by the patentee's attorney on the ground that the essential feature of each of such claims (2 to 6) was the pivoted runner and rudder, and that the Billups and Sylvester patents did not pivot their depth-runners so as to admit of a double adjustment. On the basis of this construction the patent in suit was issued.

The first claim is not in issue here. Omitting the elements "standard, share, and moldboard," which are common to all the claims, the elements of the several claims in controversy are as follows:

Second claim: "A depth-runner pivoted at its forward end to the standard, a knife or rudder pivoted at its forward end to the depth-runner, and means for independently adjusting the rear ends of the depth-runner and rudder."

Third claim: "A depth-runner pivoted at its forward end to the standard, a knife or rudder pivoted at its forward end to the depth-runner, and means for adjusting the height of the depth-runner and clamping the rear end of the rudder thereto."

Fourth claim: "A depth-runner comprising two sections pivoted at their forward ends upon opposite sides of the standard, means for adjusting the height of their rear ends and a knife or rudder pivoted at its forward end between the sections of the depth-runner."

Fifth claim: "A depth-runner comprising two sections pivoted at their forward ends upon opposite sides of the standard, means for adjusting the height of their rear ends, a knife or rudder pivoted at its forward end between the sections of the depth-runner, and means for adjusting the height of its rear end independently of the adjustment of the depth-runner."

Sixth claim: "A depth-runner comprising two sections pivoted at their forward ends on opposite sides of the standard, a knife or rudder pivoted at its