 ... by moving the telescope vertically, and read the two ends. Read the height of the crosswires on the rod. Bring the bubble near the other end of tube and read both the bubble and rod. Repeat many times. Reduce the work by taking the half-difference...  A Treatise on Surveying - Page 141902Full view - About this book
 | John Butler Johnson - Surveying - 1880 - 744 pages
...distance of the centre of the bubble from the centre of the scale. readings in each case, thus giving the distance of the centre of the bubble from the centre of tube for each position. Take the mean of these results for each set of end readings separately. If... | |
 | John Butler Johnson - Engineering - 1886 - 798 pages
...times. Reduce the work by taking the half-difference of the two end readings in each case, thus giving the distance of the centre of the bubble from the centre of tube for each position. Take the mean of these results for each set of end readings separately. If... | |
 | Walter Loring Webb - Surveying - 1895 - 84 pages
...place in the tube for the telescope in either position. Under those condition^, the wyes are level and distance of the centre of the bubble from the centre of the tube is the error of adjustment. Record this distance measured in divisions of the bubble-tube. Make... | |
 | Reginald Empson Middleton - Surveying - 1902 - 370 pages
...gave an image of the Sun, which could be comfortably observed. If this device is used, precept (6) is important on account of ' aberration.' The positions...altitude on the vertical arc, and vice versa. Example.— 59i 56* Excess of O readings over E readings = 3-ggduations 4 Centre of bubble is therefore - - 1 fl... | |
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