 This table is supported by a tripod of light construction, without leveling apparatus, the leveling of the instrument being effected with sufficient accuracy by the tripod legs. A single screw fastens the board to the tripod head, and the adjustment in...  Report - Seite 316von Maryland Geological Survey - 1898Vollansicht - Über dieses Buch
 | Geological Survey (U.S.) - 1906 - 126 Seiten
...needle 3 inches in length. (See PI. VIII.) This table is supported by a tripod of light construction, without leveling apparatus, the leveling of the instrument...compass needle; that is, it is turned until the needle rests opposite the zero marks in the compass box, and is thus always made approximately parallel to... | |
 | Charles Willard Hayes, Geological Survey (U.S.) - 1908 - 168 Seiten
...fastens the board to the tripod head and it is held in adjustment in azimuth by friction. The table is oriented by means of the compass needle; that is, it is turned until the needle rests opposite the zero marks in the compass box and is thus always made parallel to its former positions,... | |
 | Charles Willard Hayes - 1909 - 184 Seiten
...fastens the board to the tripod head and it is held in adjustment in azimuth by friction. The table is oriented by means of the compass needle; that is, it is turned until the needle rests opposite the zero marks in the compass box and is thus always made parallel to its former positions,... | |
 | Geological Survey (U.S.) - 1893 - 390 Seiten
...containing a compass needle 3 inches in length. This table is supported by a tripod of light construction, without leveling apparatus, the leveling of the instrument...needle — that is, it is turned until the needle rests opposite the zero marks in the compass box, and is thus always made approximately parallel to... | |
 | 1895 - 380 Seiten
...containing a compass needle 3 inches in length. This table is supported by a tripod of light construction, without leveling apparatus, the leveling of the instrument...needle — that is, it is turned until the needle rests opposite the zero marks in the compass box, and is thus always made approximately parallel to... | |
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