This is an OCR edition without illustrations or index. It may have numerous typos or missing text. However, purchasers can download a free scanned copy of the original rare book from the publisher's website (GeneralBooksClub.com). You can also preview excerpts of the book there. Purchasers are also entitled to a free trial membership in the General Books Club where they can select from more than a million books without charge. Original Published by: Government Printing Office in 1877 in 43 pages; Subjects: Geological surveys; Geology; Science / Earth Sciences / General; Science / Earth Sciences / Geology;