Transcriber’s notes:

In the text version, italics are represented by _underscores_, and bold and black letter text by =equals= symbols. Superscripts are represented by ^{} and subscripts by _{}.

Missing or incorrect punctuation has been repaired.
Inconsistent spelling and hyphenation have been left. This book uses both high level and standard "." in decimal numbers.

In the html version, dittos have been replaced by the repeated text so that text alignes for easier reading.

The following mistakes have been noted: