Author: R. B. MarshallPublisher: Forgotten Books
ISBN: 9781527864788
Category :
Languages : en
Pages : 118
Book Description
Excerpt from Results of Spirit Leveling in Colorado, 1896 to 1910, Inclusive Bench marks. - The standard bench marks are of two forms. The first form is a circular bronze or aluminum tablet (0 and E, Pl. 31} inches in diameter and one-fourth inch thick, having a 3-inch stem, which is cemented in a drill hole in solid rock in the wall of some public building, a bridge abutment, or other substantial masonry structure. The second form (f, Pl. I), used where masonry or rock is not available, consists of a hollow wrought-iron post 35 inches in outer diameter and 4 feet in length after being split at the bottom and expanded to a width of 10 inches in order to give a firm bearing on the earth. A bronze or aluminum-bronze cap is riveted over the top of the post, which is set about 3 feet in the ground. A third style of bench mark with abbreviated lettering (b and D, Pl. Is used for unimportant points. This consists of a special Oopper nail, 1g inches in length, driven through a copper washer seven-eighths of an inch in diameter. The tablets, as well as the caps on the iron posts, are appropriately lettered, and State cooperation is indicated by the addition of the State name (g, Pl. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
Author: R.B. Marshall
Author: Robert Bradford Marshall
Author: Robert Bradford Marshall
Author: R. B. Marshall![Results of Spirit Leveling in Delaware, District of Columbia, Maryland, and Virginia, 1896 to 1909, Inclusive. R.B. Marshall, Chief Geographer. Work Done in Cooperation with the State of Maryland During the Entire Period and with the State of Virginia in Part of 1908. [U.S. Geological Survey Bulletin 434.]. PDF](https://books.google.com/books/content/images/frontcover/_cDzwQEACAAJ?fife=w80-h100)
Author: United States. Congress. House
Author: 
Author: C. Albert White
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Author: Irving Fisher