COXK, District Judge

(after stating me tacts). The patentee substituted sheet metal for cast metal as the material for roller skate trucks. This is the beginning and end of his achievement. It is not pretended that any new function or result is attributable to the change. The skate operates in all its parts precisely'as it *1008did when the cast metal truck was used. The two structures are slightly different in appearance, but these differences are only such as are incident to the material used respectively.

The only advantages pointed out in the patent and in the proofs are that the new truck is lighter, cheaper and stronger than the old one. But these qualities are due, not to inventive skill but to good judgment in selecting the metal from which the trucks are made. There is not even a change of material as in the doorknob case (Hotchkiss v. Greenwood, 11 How. 248, 13 L. Ed. 683), but simply a change from óne variéty to another of the same material, namely from cast steel to sheet steel. If invention is to be predicated of such a change in the trucks it must necessarily be extended to similar changes in other parts of the skate. Eor instance, the substitution of hard rubber, or even a different kind of wood, as the material for the wheels -would be sufficient to support a patent, provided the change made the structure cheaper, lighter and .stronger. Invention has never been permitted to rest upon such changes alone. It is true that patents have been upheld for inventions involving change of material, but in every instance some new and useful result was accomplished or the old result was accomplished in a much better way. Where the inventor has discovered new and unknown properties residing in a given material or that a long sought for result, which has baffled an army of skilled artisairs, can be achieved by. the change, in such cases the substitution of one material for another may reach the plane of invention. But substitution alone, unaccompanied by any actual advance in the art or genuine benefit to the public, has uniformly been held insufficient to support a patent.

These differences are well illustrated by a comparison of this cause with George Frost Co. v. Cohn (decided contemporaneously) 112 Fed. 1009. The court has considered these causes together because it is difficult to conceive of better illustration of the rule referred to. Both involve a change of material in existing structures, but in the one instance the skate operates after the change precisely as it did before, and in the other a hose supporter which does not support is converted, by the change, into a hose supporter which does support. In the former case, by the use of cheaper, lighter and stronger metal the skate is made cheaper, lighter and stronger, in the other, the substitution of a rubber button for a metal button transformed a destructive and inoperative device into a highly successful one.

In Hicks v. Kelsey, 18 Wall. 670, 21 L. Ed. 852, Mr. ‘Justice Bradley states the case as follows:

“The question is -whether the mere change of material—making- the curve of iron instead of wood and iron—was a sufficient change to constitute invention; the purpose being the same, the means of accomplishing it being the same, and the form of the reach and mode of operation being the same.”

This question was answered in the negative and, as it is the precise question presented in the case at bar, the decision is controlling.

Hotchkiss v. Greenwood and Hicks v. Kelsey have been followed by an almost unbroken line of authorities since. Among those *1009most closely approximating the case at bar are the following: Florsheim v. Schilling, 137 U. S. 64, 11 Sup. Ct. 20, 34 L. Ed. 574; Iron Works v. Cassidy (C. C.) 31 Fed. 47, 24 Blatchf. 289; Kilbourne v. W. Bingham Co., 1 C. C. A. 617, 50 Fed. 697; Roofing Co. v. Garwood (C. C.) 35 Fed. 658; Strom Mfg. Co. v. Weir Frog Co., 27 C. C. A. 502, 83 Fed. 170.

It follows that the bill must be dismissed, with costs.