The gentleman's mathematical companion, for the year 1801 : Containing answers to the last year's enigmas, rebusses, charades, queries, and questions; also, new enigmas, rebusses, charades, queries & questions, proposed to be answered next year. With a curious paper, from the philosophical transactions, on the experiments of friction, by the Rev. Mr. Vince. Also, a short, but curious paper, containing, easy and general methods for solving all the cases of plane and spherical triangles, By the Rev. Walter Fisher, minister of Cranstoun.