UNITS

Except where otherwise stated, centimetre-gram-second units are employed. Temperatures are in degrees absolute centigrade. Energy, whether by itself or as involved in entropy or in specific heat, is expressed not in calories but in ergs. A power of ten standing at the beginning of a row or column of figures, and followed by a multiplication sign, is intended to multiply each number in the row or column.

LIST OF SYMBOLS

The following list shows the meanings which have been used throughout the book. Where the symbol requires an extended definition reference is made to the place where the definition will be found.

Mathematical notation is international, so that a foreigner, who is unable to read the letterpress, may yet grasp the purport of the book if he knows the meanings of the symbols only. So here I should like to explain the symbols in “the second language for all mankind”, if there were such a one. Unfortunately there are several rivals, each apparently easier to learn than any national language. Thus there are Esperanto, Ido, Esperantido, all much alike, and differing considerably from Interlingua.

A comparative study of these languages is being made by a committee of the International Research Council (at Washington, U.S.A.) and the choice of one language should rest with some supremely authoritative body.