US SUPREME COURT DECISIONS

1. Letters patent granted to Edwin L. Brady, Dec. 17, 1867, for an improved dredge boat for excavating rivers, are invalid for want of novelty and invention.

2. The design of the patent laws is to reward those who make some substantial discovery or invention which adds to our knowledge and makes a step in advance in the useful arts. It was never their object to grant a monopoly for every trifling device, every shadow of a shade of an idea, which would naturally and spontaneously occur to any skilled mechanic or operator in the ordinary progress of manufactures.

3. Although letters patent are not set up by way of defense in an answer, yet if the invention patented thereby is afterwards put into actual use, their date will be evidence of that of the invention on a question of priority between different parties.

4. One person receiving from another a full and accurate description of a useful improvement cannot appropriate it to himself, and letters patent obtained by him therefor are void.

The case is stated in the opinion of the Court.