Passages in italics were indicated by _underscores_.
Small caps were replaced with ALL CAPS.
Throughout the document, the [oe] ligature was replaced with "OE".
The illustrations have been moved so that they do not break up
paragraphs and so that they are next the text they illustrate. Thus the
page number of the illustration might not match the page number in the
List of Illustrations, and the order of illustrations may not be the
same in the List of Illustrations and in the book.
Errors in punctuations and inconsistent hyphenation were not corrected
unless otherwise noted below:
Throughout the book, "avalanch" was replaced with "avalanche".
On page 56, the single quotation mark was removed from the block-quoted
paragraph.
On page 116, "denial of of" was replaced with "denial of".
On page 230, "Amercan" was replaced with "American".
On page 296, "air-cirlces" was replaced with "air-circles".