Oliver Wendell Holmes, Jr.

“ In No. 19 the defendant's device is very like that of the plaintiff but differs in at least one particular. The plaintiff's cone, of crisp, strong, more or less rigid material, is continued in one piece under the rings that give it a rigid support. Its tympanum includes this outer edge. On the other hand, as said by Judge Thacher about another contrivance, 'the defendant's structure, although it comprises a tympanum support having a circular aperture, does not comprise a tympanum having its outer edge rigidly mounted on said support in said aperture within the meaning of claim 4. ”

“ Paper is pronounced a satisfactory material, the requirement being that it should be crisp and strong and have considerable rigidity within itself.
The state of the art at and before 1913 will be found in the cases already cited, two excellent discussions by Thacher, D. J., in Lektophone Corporation v. Western Electric Co. ”