Spelling has been made consistent throughout but reflects the author's preference.
Anchors for Page Numbers placed in line for each paragraph.
Page 22, 61, and 88 are blank pages and no page anchor was provided.
Supplement to Preface was included in the Preface.
Additional pages (to face page etc.) replaces orginal page.
Footnotes were moved to the end of the book.
Footnote [8] reference to Gric should refer to page 72 not page 71
The illustration of Specimen Mountain (pg 79) was generously made available by Internet Archive.