. Mathematics, compiled from the best authors and intended to be the text-book of the course of private lectures on these sciences in the University at Cambridge [microform]. nt to P ; then P will be the pole of the world ;whence the meridians and parallels of latitude may be pro-jected, as in the last Problem ; but they are here project-ed by ANOTHER METHOD. 1. At P, with radius PD = the semidiameter of thecircle fPi, project the quadrant Dyy, &c. E, which di-vide into nine equal parts at y, y, &c. Then draw thetangent Dxx, &c. From P reduce the points y, y, &tc, tox, x, &c. which will be the
. Mathematics, compiled from the best authors and intended to be the text-book of the course of private lectures on these sciences in the University at Cambridge [microform]. nt to P ; then P will be the pole of the world ;whence the meridians and parallels of latitude may be pro-jected, as in the last Problem ; but they are here project-ed by ANOTHER METHOD. 1. At P, with radius PD = the semidiameter of thecircle fPi, project the quadrant Dyy, &c. E, which di-vide into nine equal parts at y, y, &c. Then draw thetangent Dxx, &c. From P reduce the points y, y, &tc, tox, x, &c. which will be the centres of as many of the me-ridians. And these divisions bt ing transferred from D tou, u, Sec. will give as many other centres for other merid-ians. 2. For the parallels of latitude, tropics, equator and polarcircles, reduce the pole P to O ; from O, on each side, set10° to .», a, which reduce to the diameter V5 at b, from b on one side of P to b on the other, will be thediameter of the parallel of 10° from the pole. The othersare found in a similar manner. SPHERIC GEOMETRY. 403 Stereographic projection on tlve ecliptic. it vt. k£~ / \t It D 404 MATHEMATICS. PROBLEM VII. To project the sphere stereographkally on the plane of the tropic of Capricorn, 1. Project the equator A i Bt on the centre P, andthen draw the parallels of latitude, polar circle, and tropicin the northern part, with the meridians, as in the projec-tion on the plane of the equator. 2. Bisect the distance V? at x, and draw die eclipticT y n, &c. Divide it into the 12 signs by the proper rulein Stereographic Projection. 3. The circles of longitude and the parallels to the eclip-tic are found in the same manner, as the meridians and par-allels of latitude respectively in the last projection, SPHERIC GEOMETRY. 405 Stereographic Projection on Capricorn* N
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