Lanterna Rally

Author: George Robarts Smalley

Publisher: Rarebooksclub.com

Published: 2013-09

Total Pages: 32

ISBN-13: 9781230173924

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1862 edition. Excerpt: ...XXXVII. Parallax.--The angle subtended at an object by the line which joins two different points from which it may be viewed. ASTRONOMICAL RESULTS AND LAWS. 1. The motions of all the planets in their orbits are from west to east, and are all subject to Kepler's Laws. 2. Kepler's Laws.--(1) The radii vectores describe areas in one plane proportional to the time. (2) The orbits are ellipses having the sun in one of their foci. (3) The squares of the periodic times are proportional to the cubes of the mean distances from the Sun. 3. Deductions from Kepler's Laws.. From Law (1)--the force which acts upon the bodies tends always to the centre of the sun. From Law (2)--the force varies inversely as the square of the distance. From Law (3)--the absolute force is the same for all the planets. 4. Bode's Law.--Vide Appendix, Table XVI. ASTRONOMICAL FORMULAE. Notation. I, c denote the latitude and colatitude of a place. 8, p the declination and polar distance of a celestial body. z and z' the true and apparent zenith distances. A or a and A' or a' altitudes. h hour angle. 1. Distance (D miles) of the offing or visible horizon from the eye, height k feet); And Dip (a minutes), D = /-h approximately, a =-9784 /J 2. Latitude by the sun's meridian altitude, I = 8 + z. 3. Latitude by a circumpolar star, -A + a I __. 4. Latitude by the pole star out of the meridian, I = a--p cos h + 5 tan a (p sin h)2 sin 1." 5. Hour angle, by an observed altitude: j / + h. / sin--9-V 6. Length of day (2i), cos (t X 15) =--tan /. tan 8. 7. Refraction, = 57" tan z' nearly. 8. Parallax in altitude, 10. Longitude by the chronometer, = Greenwich time-corrected time at any place. Longitude by lunar distances, (l)sinsf =...