United States or United States Virgin Islands ? Vote for the TOP Country of the Week !
The quadrant of Ptolemy resembled the mural quadrant of later times; which, however, was improved by the Arabians, who, at the end of the tenth century, employed a quadrant twenty-one feet and eight inches radius, and a sextant fifty-seven feet nine inches radius, and divided into seconds.
One of the books which he read at this time directed his attention to astronomical instruments, and he was thus led to construct for himself a quadrant, by which he could take some simple astronomical observations. He further calculated a table to give the sun's altitudes at different hours, and thus displayed those tastes for practical astronomy which he lived to develop so greatly.
"Young Vesputius is one to whom Americus Vesputius his uncle left the exact knowledge of the mariner's faculties, as it were by inheritance, after his death; for he was a very expert master in the knowledge of his carde, his compasse and the elevation of the pole starre by the quadrant.... Vesputius is my very familiar friend, and a wittie young man, in whose company I take great pleasure, and therefore use him oftentymes for my guest.
Ptolemaeus, in the third quadrant, and not far removed from the centre of the disc, may be taken as a typical example of the class. Here we have a vast plain, 115 miles from side to side, encircled by a massive but much broken wall, which at one peak towers more than 9000 feet above a level floor, which includes details of a very remarkable character.
At this moment the men, one and all, still grasping their respective slew-ropes firmly in their hands, and without bending a joint in their whole bodies, fell simultaneously on their backs, flat on the water! The effect of this sudden movement was to turn the cylinder a full quadrant, or one quarter of a revolution. This, of course, brought a considerable strain on the hawser fixed to the anchor.
In 1568 Tycho left Rostock, and matriculated at Basle, but soon moved on to Augsburg, where he found more enthusiasm for astronomy, and induced one of his new friends to order the construction of a large 19-foot quadrant of heavy oak beams.
"Oh, nothing, except lots of human skeletons, and whitings in abundance, swimming between their ribs. I brought up my old quadrant out of the starboard wing, where I was adjusting it when the alarm was given. I found it lying on the table just where I left it.
Biscuits, salt pork, two or three small casks of water, and a barrel of rum were collected at the gangway; Mackintosh brought up his quadrant and a compass, some muskets, powder and shot; the carpenter, with the assistance of another man, cut away the ship's bulwarks down to the gunnel, so as to enable them to launch the boat overboard, for they could not, of course, hoist her out now that the masts were gone.
It was not possible to make the initial movements in the direction of the eventual advance, as the Magersfontein-Brown's Drift quadrant N.E. of Modder River was strongly held by the enemy, and disallowed a cavalry advance from below the junction of the Riet and the Modder in the direction of Kimberley except by a westerly detour which could not be accommodated to the general scheme.
The middle of this compound figure is decorated with a cross, and in each quadrant there is a row of the same emblems, equidistant from one another. It would be but a short step from this figure to the ancient sun symbol with which the eagle and other raptorial birds are intimately associated.
Word Of The Day