2. The patent act of congress of July 4, 1836, sect. 6, in describing the subjects of patents, mentions "new and useful art," and "new and useful improvement." To entitle the inventor to a patent, his invention must, to a certain extent, be beneficial to the community, and not be for an unlawful object, or frivolous, or insignificant. 1 Mason, 182; 1 Pet. C. C. R. 322; 1 Bald. 303; 14 Pick. 217; Paine, 203.