THE author makes his title, “Quick and Easy Methods of Calculating”—at least, that is all that is in large print on the title-page; but the binder calls it, on the outside of the book, “The Slide-Rule ...

THE following mechanical method of finding logarithms seems to be as simple as any that have been proposed, and has the advantage that it gives the logarithms of all numbers without interpolation, and ...

A logarithm is the power which a certain number is raised to get another number. Before calculators and various types of complex computers were invented it was difficult for scientists and ...