 If the true and magnetic amplitudes be both north or both south, their difference is the variation ; but if one be north and the other south, their sum is the variation; and to know whether it be easterly or westerly, suppose the observer looking towards...  A complete epitome of practical navigation - Page 191by John William Norie - 1839Full view - About this book
 | Robert Gibson - Surveying - 1811 - 580 pages
...north and the other south, their sum is the variation ; and to know whether it be easterly or westerly, suppose the observer looking towards that point of the compass representing the magnetic amplitude; then if the true amplitude be to the right hand of the magnetic amplitude, the variation... | |
 | Surveying - 1814 - 398 pages
...difference is the variation: but if one be on the east and the west side of the meridian, their sum is the variation ; and to know if it be east or west,...left of the magnetic, the variation is west. EXAMPLE. November g, 1812, in latitude 25° 32' N. and longitude 75° W. the altitude of the sun's lower limb... | |
 | Surveying - 1814 - 402 pages
...north and the other south, their sum is the variation ; and to know whether it be easterly or westerly, suppose the observer looking towards that point of the compass representing the magnetic amplitude. Then if the true amplitude be to the right hand of the magnetic amplitude, the variation... | |
 | Robert Gibson - Surveying - 1814 - 558 pages
...north and the other south, their sum is the variation ; and to know whether it be easterly or westerly, suppose the observer looking towards that point of the compass representing the magnetic amplitude : then if the true amplitude be to the right hand of the magnetic amplitude, the variation... | |
 | John William Norie - 1840 - 184 pages
...the other south, their sum will be the variation ; and to know whether it be easterly or westerly, suppose the observer looking towards that point of the compass representing the magnetic amplitude ; then, if the true amplitude be to the ri^ht hand of the magnetic, the variation is east,... | |
 | Janet Taylor - Nautical astronomy - 1842 - 592 pages
...and the other from the south, take the supplement of the true azimuth, and the differenee between it and the magnetic azimuth will be the variation ; and...to know if it be east or west, suppose the observer to be looking towards that point of the compass which represents the true azimuth, when if the magnetic... | |
 | Basil Jackson - Military reconnaissance - 1847 - 410 pages
...and the other south, their sum is the variation : and, to know whether it be easterly or westerly, suppose the observer looking towards that point of the compass representing the magnetic amplitude ; then, if the true amplitude be to the right hand of the magnetic, the variation is east,... | |
 | Janet Taylor - Nautical astronomy - 1851 - 674 pages
...difference is the variation ; but if one be computed from the north and the other from the south, take the true azimuth from 180°, and the difference between...to know if it be east or west, suppose the observer to be looking towards that point of the compass which represents the true azimuth, when if the magnetic... | |
 | Janet Taylor - 1865 - 184 pages
...difference is the variation; but If one be computed from the north, and the other from the south take the true azimuth from 180°, and the difference between...and the magnetic azimuth will be the • variation. To find whether the variation is E. or W. the observer must look from the centre of the compass towards... | |
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