 Let the board be placed about one foot in front of the theodolite, a lamp or candle placed on the shelf at its lower edge ; and let the board be slipped up or down, until the pole-star can be seen through the hole. The light reflected from the paper will...  Elements of Surveying: With the Necessary Tables - Page 100by Charles Davies - 1830 - 306 pagesFull view - About this book
 | United States. General Land Office - Public lands - 1881 - 138 pages
...pole-star can be seen through the hole. The light reflected from the paper will show the cross hair« in the telescope of the theodolite. Then, let the vertical spider's line be brought exactly upoii the polestar, and if it is an eastern elongation that is to be observed, and the star has not... | |
 | United States. Bureau of Land Management - Surveying - 1890 - 192 pages
...seen through the hole. The light reflected from the paper will show the cross hairs in thé telescope. Then, let the vertical spider's line be brought exactly...is to be observed, and the star has not yet reached the most easterly point, it will move from the line toward the east, and the reverse when the elongation... | |
 | South Australia. Surveyor-General's Office - Surveying - 1914 - 200 pages
...held near the object glass of the telescope, then watch the star at intervals of about two minutes. If it is an eastern elongation that is to be observed, and the star has not yet reached its most easterly point, it will move away from the cross hairs towards the east and upwards at the... | |
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