Punctuation, some hyphenation, and spelling were made consistent when a predominant preference was found in the original book; otherwise they were not changed. The original book inconsistently followed “electro” with a hyphen, and that has not been changed here.
Simple typographical errors were corrected; unbalanced quotation marks were remedied when the change was obvious, and otherwise left unbalanced.
Illustrations in this eBook have been positioned between paragraphs and outside quotations. In versions of this eBook that support hyperlinks, the page references in the List of Illustrations lead to the corresponding illustrations.
Running page headers in the original book are shown here with a gray background (in ereaders that support shaded backgrounds), placed between paragraphs and near the topics to which they refer.
Footnotes, originally at the bottoms of pages, have been renumbered into a single sequence, collected, and moved to just above the Index.
The index was reformatted slightly and was not checked systematically for proper alphabetization or correct page references.