the value of Farrow's alleged invention, even when coupled with its covenant to use due business diligence in pushing their sale, did not preclude it from using any later invention, if one were made which superseded Farrow's, and did not embody it. Due business diligence would not require it to enter into a hopeless contest, and would not prevent it from avoiding such a contest by purchase. In that event it would not be accountable to Farrow for royalties on the new machine. See Thorn Wire Hedge Co. v. Washburn & Moen Manufacturing Co., 159 U. S. 423.

Applying this construction to the case, there is little difficulty in arriving at our judgment. The defendant at the original hearing, when the first Morrow device alone was in question, offered no evidence to controvert that of the plaintiff's expert that it was a palpable attempt to evade Farrow's rights. Its argument upon that point before us depended largely upon the contention that in view of the state of the art Farrow's claims must be narrowly limited, and gave too little effect to the contract. It is evident from the latter as well as from the evidence that a patent of a certain breadth was expected. The plaintiff, on the other hand, did not chiefly rely upon maintaining that the second device, E 10, would have been an infringement of any patent that the contract can be taken to have contemplated, but depended mainly upon construing the contract as binding the defendant to pay royalties if any other than Farrow's braking and coasting device were used. Therefore a summary statement of the nature of the different devices is all that is necessary to complete our disposition of the case.

In Farrow's application and Morrow's first device there was the same clutch mechanism on the rear wheel to permit coasting, and in both a contrivance for bringing a brake shoe to bear upon the rear wheel by back pedalling. Farrow accomplished this result by means of a hood pivoted to the bicycle frame, embracing the upper run of the chain and having a pivoted tooth or pawl. With the hood is connected a rod having the brake shoe on its end. Back pedalling, causing the chain to

slacken, lets it drop down upon the pawl and engage it, and thereby pulls back the hood and rod and brings the brake shoe to bear. By a second device, which the defendant is not in a position to say was not patentable, the brake was applied by the front instead of the rear sprocket wheel, which in case of back pedalling engaged a lever and put on the brake. Morrow used the front sprocket wheel and made it apply a lever with a brake shoe by means of a clutch. The details of the means of application differ, but it cannot be doubted that assuming the novelty in Farrow's invention which the contract assumes, Morrow, in the language of the contract, was embodying that invention. It covered the very thing which Farrow's invention was expected and mainly relied on to supply. Taking into account the fact that the defendant did not make due efforts to carry out his application, and that it certainly does not appear that the Morrow device was so much, if at all, better than Farrow's, that due business diligence did not require the company still to push the latter, we are of opinion that on this item it properly was held to account.

Farrow also embraced a hub brake in his applications. One of his devices was to have the rear sprocket wheel connect with the hub of the rear wheel by a screw clutch. When the sprocket wheel was moving forward it was screwed into fixed connections with the hub. When the pedals were held fast, so as to hold the sprocket wheel also fast through the medium of the chain, the bicycle, continuing its motion, unscrewed the sprocket wheel from the hub, disconnected it and coasted. Back pedalling brought a projection on a spring in and attached at one end to the rear sprocket and encircling the hub, into contact with a fixed point on the frame, and thus caused the spring to embrace the hub so long as pressure was applied. On the presure being released, the spring expanded and allowed the hub to revolve loosely within it. In the coasting or braking, it will be seen, the sprocket wheel was moved along its axis a short distance outward from the rear wheel, thus giving a slant to the chain. When a forward movement was resumed the tendency

of the chain under the pressure upon it to get back into a straight line was enough to carry the sprocket wheel inward again upon its axis so as to lock it once more to the rear wheel by the screw clutch. There are further details, but this simple outline is enough for our purposes, which are only those of broad comparison and contrast.

In Exhibit E 10 the characteristic lateral motion of the sprocket wheel on the extension of the hub does not appear, and neither Farrow's rotating brake spring nor his lever is used. The engagements are effected by the movement of a clutch ring with cam inclines, the sprocket wheel having coöperating cam inclines. When the sprocket wheel moves forward the latter cam inclines ride upon the former, force the clutch ring inward and allow it to grasp the hub by friction and revolve with it. On back pedalling the square shoulders of the cam inclines engage, the clutch ring is moved backward with the sprocket wheel, and cam inclines on the inner side of the ring force a brake ring inward into a hollow conical brake shoe connected with the frame of the machine and having no rotary movement. The brake shoe thus is forced inwardly into a brake cup and effects the braking by its friction. In this case, as in the former, a general indication of the nature of the device is sufficient on the question whether the latter embodies the former in the sense of the contract. This question is answered by the description which we have given. It is true that in both the sprocket wheel is arranged to engage or disengage with the main wheels of the machine, to allow coasting and to brake by a reverse action of the rider's feet. But the methods by which these results are accomplished are so different that it is only on the assumption that Farrow was in the broadest sense a pioneer, and had covered the whole ground, or at least that the contract put him in that position relatively to the defendant that the claim in respect of E 10 could be allowed. It is not pretended that Farrow occupied such a position as an inventor, and our construction of the contract does not give it the supposed extent. The auditor found that there was a radi

cal difference between the contrivances in construction and operation, and there has not been and could not be a finding to the contrary. The ground on which the account was ordered was that the contract required it, notwithstanding all the difference which the auditor found. We could not come to that conclusion unless we at least were satisfied that it was inconsistent with due business diligence in pushing Farrow for the defendant to take up with E 10. The witnesses pointed out important superiorities in the latter, which we need not repeat, in the way of avoiding clogging by mud or ice, in applicability to a chainless machine, in more immediate and certain operation, and in requiring a less continuous exercise of force. On these points they were not contradicted. If, as we think, E 10 did not embody Farrow's invention, and if the company reasonably and honestly thought it a better thing, it had a right to do what it did. We cannot say that it was not warranted in its preference of E 10, or that it was not honest in its choice. It follows that with regard to this the decree must be reversed.

There was evidence that the defendant had sold out to another company of a nearly similar name. It is enough to say that it does not appear that the defendant is not still in existence, but on the contrary it would seem that the corporation still exists.

Decree reversed and case remanded with directions to reinstate

the auditor's first report so far as the same disallows a claim in respect of E 10.

199 U. S.

Argument for Plaintiff in Error.

MINNESOTA IRON COMPANY v. KLINE.

ERROR TO THE SUPREME COURT OF THE STATE OF MINNESOTA.

No. 96. Argued December 5, 1905.-Decided December 18, 1905.

If a state statute as interpreted by the highest court of the State is not violative of the Federal Constitution this court will accept the construction of the state court.

The statute of Minnesota, G. S., 1894, § 2701, providing that the liability of railroad companies for damages to employés shall not be diminished by reason of the accident occurring through the negligence of fellow servants, and excepting from its provisions damages sustained by employés engaged in construction of new and unopened railroads, does not, as interpreted by the highest court of that State, discriminate against any class of railroads or deny to such class the equal protection of the laws; the exception merely marks the time when the statute takes effect. There is no objection under the Fourteenth Amendment to legislation confined to a peculiar and well-defined class of perils, and it is not necessary that they are shared by the public if they concern the body of citizens engaged in a particular work.

Freedom of contract may be limited by a state statute where there are visible reasons of public policy for the limitation.

THE facts are stated in the opinion.

Mr. Frank B. Kellogg, with whom Mr. W. W. Billson and Mr. Joseph B. Cotton were on the brief, for plaintiff in error: The statute as construed by the Supreme Court of the State, denies to plaintiff in error the equal protection of the laws.

The sole circumstance relied upon to bring the defendant, a private mining company, under the operation of the statute, is that it used steam power trains in moving earth from cut to fill.

As construed by the state court, the function of the proviso in the statute is to exempt certain railroad employers from the operation of the act, on the ground of the newness of their roads.

As to the irrationality of the distinction between new and oid VOL. CXCIX-38