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 as printed.

Greek words in the text can be rendered onto ascii as follows:—

The following changes have been made

p. 79.	emananting changed to emanating
p. 142.	Rolandshay changed to Ronaldshay
p. 285.	montony changed to monotony
p. 299.	Ronaldsha changed to Ronaldshay
p. 318.	Index, Paris, Matthew reference changed from p. 23. to 213.
p. 322.(the Index of Illustrations)	Fresner's changed to Fresnel's
p. 322.	Cordouan is used but the illustration caption uses Cordova. This has been left as printed.