There is a simple non-algebraical and very clear explanation of logarithms; then the real object of the book, an explanation of the slide-rule, follows.

That's because the earthquake scale—called the Moment Magnitude Scale, which replaced the Richter Scale—is logarithmic, rather than arithmetic.

This includes basic notions such as sets and functions: Properties of sets, definition and properties of functions; logarithms and exponentials: and their properties; basic series summations: ...

This includes basic notions such as sets and functions: Properties of sets, definition and properties of functions; logarithms and exponentials: and their properties; basic series summations: ...