INDEX. The numeral Figures refer to the Pages, and the small n to the Notes subjoined. A. ACCELERATION of the stars, 160. Eras or epochs, 421. Angle, under which an object appears, what, 128, n. Anomaly, what, 176. Ancients, their superstitious notions of eclipses, 303. Their method of dividing the zodiac, 381. Antipodes, what, 86. Apsides, line of, 176. ARCHIMEDES, his ideal problem for moving the Earth, 112. Areas, described by the planets, proportional to the times, 109. Astronomy, the great advantages arising from it both in our religious and civil concerns, 31. Discovers the laws by which the planets move, and are retained in their orbits, 31. Atmosphere, the higher the thinner, 121. Its prodigious expansion, 121. Its whole weight on the Earth, 122. Generally thought to be heaviest when it is lightest, 123. Without it, the heavens would appear dark in the day-time, 123. Is the cause of twilight, 124. Its height, 124. Refracts the Sun's rays, 124. Causeth the Sun and Moon to appear above the horizon when they are really below it, 124. Foggy, deceives us, in the bulk and distance of objects, 129. Attraction, 76. Decreases as the square of the distance increases, 76. Greater in the larger than in the smaller planets, 112. Greater in the Sun, than in all the planets if put together, 112. Axes of the planets, what, 38. Their different positions with respect to one another, 83. Axis of the Earth, its parallelism, 145. Its position variable as seen from the Sun or Moon, 308. The phenomena, thence arising, 310. B. Bodies, on the Earth, lose of their weight the nearer they are to the equator, 82. How they might lose all their weight, 83. How they become visible, 117. C. Calculator (an instrument) described, 437. Calendar, how to inscribe the Golden numbers right in it for shewing the days of new Moons, 396. Cannon-ball, its swiftness, 68. In what times it would fly from the Sun to the different planets and fixed stars, 68. CASSINI, his account of a double star eclipsed by the Moon, 53. His diagrams of the paths of the planets, 98. Catalogue of the eclipses, 282. Of the constellations and stars, 382. Of remarkable æras and events, 421. Celestial globe improved, 447. Centripetal and centrifugal forces, how they alternately over come each other in the motions of the planets, 108, 110. Changes in the heavens, 385. Circles, of perpetual apparition and occultation, 91. Contain 360 degrees whether they be great or small, 152. Civil year, what, 309. COLUMBUS (CHRISTOPHER) his story concerning an eclipse, Clocks and watches, an easy method of knowing whether they go true or false, 164. Why they seldom agree with the Sun if they go true, 168-181. How to regulate them by equation-tables and a meridianline, 166. Cloudy stars, 384. Cometarium (an instrument) described, 444. Constellations, ancient, their number, 380. The number of stars in each, according to different as tronomers, 382. Cycle, solar, lunar, and Roman, 395. D. Darkness at our SAVIOUR's crucifixion supernatural, 317416. Day, natural and artificial, what, 394. And night, always equally long at the equator, 90. Natural, not completed in an absolute turn of the Earth on its axis, 164. Degree, what, 152. Direction, (number of), 412. Distances of the planets from the Sun, an idea of them, 68. A table of them, 73. How found, 132; and in the Dissertation on the transit of Venus, chap. XXIII. Diurnal and annual motions of the earth illustrated, 141— 145. Dominical letter, 413. Double projectile force, a balance to a quadruple power of gravity, 109. Double star covered by the Moon, 52. E. Earth, its bulk but a point as seen from the Sun, 32. Its diameter, annual period, and distance from the Sun, 49. Turns round its axis, 49. Velocity of its equatorial parts, 49. Velocity in its annual orbit, 49. Inclination of its axis, 49. Proof of its being globular, or nearly so, 50, 261. Difference between its equatorial and polar diameters, 59. Its motion round the Sun demonstrated by gravity, 77, 78, by Dr. BRADLEY'S observations, 80, by the eclipses of Jupiter's satellites, 158. Its diurnal motion highly probable from the absurdity that must follow upon supposing it not to move, 78, 86, and demonstrable from its figure, 87, this motion cannot be felt, 83. 30 seconds at Greenwich: so that he must have seen it 2 minutes 30 seconds sooner in absolute time than it was seen at Greenwich-a difference by much too great to be occasioned by the difference of parallaxes. But by a memorandum of Mr. Haydon's some years before, it appears that he then supposed his west longitude to be near two minutes more; which brings his time to agree within half a minute of the time at Greenwich; to which the parallaxes will very nearly answer. At Stockholm observatory, latitude 59° 20' north, and longitude 1 hour 12 minutes east from Greenwich, the whole of the transit was visible; the total ingress was observed by Mr. Wargentin to be at 3 hours 39 minutes 23 seconds in the morning, and the beginning of egress at 9 hours 30 minutes 8 seconds; so that the whole duration between the two internal contacts, as seen at that place, was 5 hours 50 minutes 45 seconds. At Torneo in Lapland (1 hour 27 minutes 28 seconds east of Paris) Mr. Hellant, who is esteemed a very good observer, found the total ingress to be at 4 hours 3 minutes 59 seconds; and the beginning of egress to be 9 hours 54 minutes 8 seconds.-So that the whole duration between the two internal contacts was 5 hours 50 minutes 9 seconds. At Hernosand in Sweden (latitude 60° 38′ north, and longitude 1 hour 2 minutes 12 seconds east of Paris), Mr. Gister observed the total ingress to be at 3 hours 38 minutes 26 seconds; and the beginning of egress to be at 9 hours 29 minutes 21 seconds. The duration between these two internal contacts 5 hours 50 minutes 56 seconds. Mr. De La Lande, at Paris, observed the beginning of egress to be at 8 hours 28 minutes 26 seconds apparent time-But Mr. Ferner (who was then at Constans, 14" west of the Royal Observatory at Paris) observed the beginning of egress to be at 8 hours 28 minutes 29 seconds true time, |
