 | Mary Somerville - 1831 - 710 pagine
...accumulation and deficiency determine the two poles of this great magnet, which are by no means the same as the poles of the earth's rotation. In consequence...north and south, are called lines of no variation, and are extremely complicated. The direction of the needle is not even constant in the same place, but... | |
 | Mary Somerville - 1831 - 720 pagine
...through all the places where the needle points due north and south, are called lines of no variation, and are extremely complicated. The direction of the needle...1657, the line of no variation passed through London. In the yenr 1819, Captain Parry, in his voyage to discover the north-west passage round America, sailed... | |
 | 1832 - 650 pagine
...accumulation and deficiency determine the two poles of this great magnet, which are by no means the same as the poles of the earth's rotation. In consequence...north and south, are called lines of no variation, and are extremely complicated. The direction of the needle is not even constant in the same place, but... | |
 | Mary Somerville - 1834 - 390 pagine
...with that of the galvanic battery, the electricity of the under surface of the fish being the sajne with the negative pole, and that in the upper surface...few years according to a law not yet determined. In 1667, the line of no variation passed through London ; from that time it has moved slowly, but irregularly,... | |
 | Benjamin Silliman - 1837 - 118 pagine
...which passes through the north and south magnetic poles. There are places where the magnetic meridan coincides with the terrestrial meridian ; in these...few years according to a law not yet determined. In 1667, the line of no variation passed through London ; from that time it has moved slowly, but irregularly,... | |
 | James Bonwick - 1845 - 228 pagine
...obliged to make allowances for these variations in their reckonings. The lines drawn on the globe through places where the needle points due north and south are called lines of no variation. One line of no variation runs from the north magnetic pole through Washington, and through Bahia in... | |
 | Mary Somerville - 1846 - 496 pagine
...direction will deviate, sometimes to the east, and sometimes to the west of the true north. Imaginary lines drawn on the globe through all the places where...north and south are called lines of no variation. Imaginary lines drawn through all those places where the needle deviates from the geographical meridian... | |
 | John Leifchild - 1849 - 276 pagine
...it. This tendency to change is termed the variation of the needle, and was noticed in the year 1500. Lines drawn on the globe through all the places where...no variation, and they are extremely complicated. Again, an unmagnetized needle, suspended so as to be freely movable in a vertical plane, (that is,... | |
 | Archibald Tucker Ritchie - 1850 - 678 pagine
...there to be a divergency between the poles (if rotation and those of terrestrial magnetism. — AUTHOR. suspended, points to the true north ; but, if it be...variation, and they are extremely complicated. ..... " The needle is also subject to diurnal variations. In our latitudes it moves slowly westward during the... | |
 | Archibald Tucker Ritchie - 1850 - 648 pagine
...direction will deviate sometimes to the east and sometimes to the west of north. Lines drawn on the glohe, through all the places where the needle points due...variation, and they are extremely complicated " The needle is also suhject to diurnal variations. In our latitudes it moves slowly westward during the... | |
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... that is, in the plane which passes through the north and south magnetic poles. There are places where the magnetic meridian coincides with the terrestrial meridian ; in these a magnetic needle freely suspended, points to the true north, but if it... 
