Transcriber's Notes
Reading edition
The following typographical corrections have been made:
Page x: Heat without combustion—Inter-currents{original had no hyphen; changed to match page 45, to which it refers}
Page xiii: The fifth plate (from the Addendum) has been added to the list of illustrations.
Page 60: back and forth to maintain an{comma removed} equilibrium.
Page 64: {quotation mark removed}The course of a balloonist
Page 102: {quotation mark added}"These clouds sometimes range themselves
Page 107: {quotation mark added}"The overwhelming probability of a common cause
The following inconsistent hyphenation is as printed:
Page 42: just such a retro-acting inter-communication.
Page 72: might interfere with the intercommunication of light