Transcriber’s Notes
Reading edition
Retained publication information from the printed edition: this eBook is public-domain in the country of publication.
Corrected a few palpable typos.
Re-arranged text in captions closer to the corresponding image.
Expanded ambiguous references to illustrations, e.g. “Figure D” to “Figure 16D”
Added one section heading, “The First Big Lake” to match the table of contents.
Included a transcription of the text within some images, with estimated scale readings from charts.
In the text versions only, text in italics is delimited by _underscores_.