NEW AND USEFUL INVENTION. This phrase is used in tlie act of congress relating to granting patents for inventions.

2. The invention to be patented must not only be new, but useful; that is, useful in contradistinction to frivolous or mischievous inventions. It is not meant that the invention should in all cases be superior to the modes now in use for the same purposes. 1 Mason's C. C. R. 182; 1 Mason's C. C. R. 302; 4 Wash. C. C. R. 9: 1 Pet. C, C. R. 480, 481; 1 Paine's C. C. R. 203; 3 Mann. Gr. & Scott, 425. The law as to the usefulness of the invention is the same in France. Renouard, c. 5, s. 16, n. 1, page 177.