302 GEOGRAPHY ANd ASTRONOMY. So 6 0 figure xxiv. is the sign of the sun's hourfrom 6 ; but the radius is 6 n, and the number of degrees in 6 Q is to be found in this manner.- Take'the extent 6 e, or this whole lesser radius in your compasses, and set it from b to q in figure xxv. then take the extent 6.0, and setting one foot of the compasses in q, make an obscure arch at o, and a ruler laid from b the centre by the edge of that arch o will find the point din the limb, and shew that dy is 34f. degrees, which (turned into hours) is two hours 17 minutes from six, viz. 17 minutes past eight in the morn- ing, to 13 minutes past three in the afternoon. , Again F O in figure xxiv. is the sine of the azimuth from east to west to the radius r A ; take therefore r A in your com- passes and set it from h toy in figure xxv. then take the extents ,Q and with one foot in p make the obscure arch a ; by the edge of that arch lay a ruler from b the centre, and you will find the point sin the limb ; thereforey s is the azimuth from east to west, that is, about 17 degrees. Note, If you have the instrument called a sector at hand and know how to use it, you may with great ease and exactness find the value of any sine in the analemma, whether it be to a greater or a lesser radius, without these geometrical operations. ProblemXX. "'l'o find the sun's place in the ecliptic any day in the year." It is well known that the 12 signs of the zodiac, each of which has 30 degrees, contain in all 360 degrees : and the sun is said to go through them all at once in twelve months or a year. Therefore ina vulgar account, and for the use of learners, wege- nerally say, the sun goes through one degree in a little more than day, and thereby finishes the 360 degrees in 365 days. But this is not the justest and most accurate account of things : let us therefore now toward the end of this book, with a little more exactness observe, 1. That the annual course which the sun appears to take through the ecliptic round the earth, is much more properly and truly ascribed to the earth's moving or taking its course round the sun ; though the common appearances to our eye are much the same as if the sun moved. 2. Thisannual course or path of the earth is not properly a circle, but an ellipsis or oval : And as the sun is fixed in one of 'the focus's of the ellipsis, so the fixed stars, (and among them the 12 signs,) surround and encompass it. See figure xxxt. where the black point t is the earth in its orbit moving round, and C) the sun near the middle, and the outward circle of points is the starry heaven. 3. Thatpart of this ellipsis or oval, which the earth traces in our winter half-year, (i. e. from autumn to spring) is nearer to
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