ASTRONOMY.
Of the appearance of the Sun, as seen from Mercury , It’d.
The rotation of Mercury upon his axis unknown, ibid.
Of the phenomena of the Solar spots seen from Mercury , ibid.
Of the phxnomena of the other planets as m en hom Mercurv,127.
Of the phamomena of Venus as seen from the Earth , 128.
The telescopic appearances of Venus , ibid.
The supposition of the planet Venus having a satellite disproved,ibid.
Sect. VII. Of the Transits of Venus and Mercury ,(1‘29-133.)
Under what circumstances Mercury and Venus must be in orderto pass over the Sun ’s disk as a round black spot, 129-
The transits of Mercury and Venus , (especially those of the lat-ter,) of great importance in Astronomy, ibid.
Kepler , the first who ventured to predict the time of a transit offiler ury and Venus , ibid.
Gassendi , the first upon record that ever saw a transit, ibid.
M. De La I.ande’s periods of the return of the transits of Mer-cury , ibid.
Table of the Transits of Mercury calculated for the 17th, 18th,and 19th Centuries, from M. De La Laude’s Tables, and re-duced to the meridian of Greenwich, 130.
Table of the Transits of Mercury calculated for the 20th Centuryby means of the periods, 131.
De La Lande’s periods of the return of Venus upon the Solardisk, 132.
Table of the Transits of Venus from A. D. 1031 to A. D. 2984,(both inclusive), 133.
Sect. VIII. Of the Figure, Motion, &c. of the Earth ,(134-146.)
Different opinions respecting the form of the Earth , 134.
The figure of the Earth demonstrated to be very nearly spherical,ibid.
The figure of the Earth demonstrated by Sir Isaac Newton andMr. Huygens to be that of an oblate spheroid, ibid.
The figure of the Earth being an oblate spheroid confirmed byactual admeasurement, 134, 135.
The perpetual succession of day and night, and the apparent diur-nal revolution of all the heavenly bodies, explained, 136.
The phxnomena of the seasons, explained, 137, 138.
The Sun being upwards of three millions of miles nearer to theEarth on the first day of January than he is on the first of July 7 ;why we have not the hottest weather in the winter-months,138.
Of the tropical, Julian, and sidereal year, 139.
The precession of the equinoctial points defined and explained,139—141.
Of the great differences that may exist between real and apparentmotion considered in vindication of the Earth ’s motion, 142.
Of the nutation of the Earth ’s axis, 143.
Of refraction, 144.
Dr. Bradley’s Table of the mean Astronomical Refractions inAltitude,"corrected by the late M. De La Laiule, 145.
The phxndurena of the twilight explained, ,146.
Sect . IX. Of the Phenomena of tiie Moon,
(147-155.)
Of the appearance of the Moon to the naked eye, and through atelescope, 147.
The names of the principal lunar spots, according to Iliccioli,Cassini, and Mayor, 148.
Of the inequalities of the Moon ’s surface, 149.
How the lunar mountains may be measured, ibid.
Volcanoes discovered in the Moon , ]50.
Of the constantly varying phases of the Moon , 151.
Our Earth a Moon to the inhabitants of the Moon , 152.
The lunar phases further explained, 153.
Of the pha’itomena of the lunar cusps, ibid.
The Moon turns round her axis in the time she moves round theEarth , ibid.
Why the Moon takes a longer time to move from the Sun to theSun again than to go round once in her orbit, explained, ibid.
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Principal elements of the lunar theory collected by M. de LaLande from the best observations, 154, 155.
Sect. X. Of the Tides , (156-162.)
The tides are found to follow periodically the course of theMoon , 1-56.
Kepler , the first who accounted in a rational manner for thetides, ibid.
The principal phenomena of the tides minutely detailed, ibid.
The tides demonstrated to result from'the action of the Sun andMoon, 156—161.
Of spring and neap-tides, 160.
Conjecture respecting atmospheric tides, 162.
Sect. XI. Of the Harvest Moon, (163.)
The phxnomenon of the harvest-moon explained, 163.
Of the most advantageous and least beneficial harvest-moons, ibid,
Sect . XII. Of the Horizontal Sun and Moon, (164.)
Alhazen’s opinion why the Sun and Moon appear larger in thehorizon, than when elevated above it, 164.
DesCartes and Dr. Wallis opinion respecting this phxnomenon,ibid.
Dr. Desagulier’s and Dr. Smith’s opinions, ibid.
Sect. XIII. Of the Phenomena of the SueeriorPlanets, (165—^—171.)
Of the different phxnomena of Mars as seen from the Earth , 165.
The telescopic appearance of Mars , ibid.
The phamomena of the other planets as seen from Mars , ibid.
Dr. lderschel’s discoveries respecting this planet, ibid.
Of the telescopic, appearances of Jupiter , 166.
Of the phxnomena of Jupiter ’s satellites, 166, 167.
Dr. Herschel’s discovery that the satellites of Jupiter turn roundtheir primary exactly in the time that they perform their pe-riodic revolutions respectively, 167.
Saturn 's telescopic appearances, 168.
The phxnomena of Saturn ’s rings, ibid.
Account of the seven satellites of Saturn , 169.
Of the phxnomena of the Georgium Sidus, 170.
Of the six satellites of the Georgium Sidus, ibid.
The Georgium Sidus probably seen as a fixed star before the timeof l)r. Herschel, ibid.
A brief account of the four new planets, Ceres , Pallas, Juno, andVesta, 171.
Sect. XIV. Of the Phenomena of Comets , (172--195.)
Comets opaque spherical bodies, like the planets, 172.
The opinions of the ancients concerning comets, ibid.
Comets, in the dark and superstitious ages, deemed portentous,173.
Kepler ’s strange opinion respecting comets, 174.
The quaint opinion of John Bodin respecting comets, 175.
James Bernouilli supposed them to be the satellites of some verydistant planet, 176.
Tycho Brahe ’s observations on the comet of 1577, 177.
Comets proved to be much further from the Earth than the Mooais, 17S.
The figures of comets observed to be very different from one ano-ther, 179.
Ofthe different phxnomena of the tails of comets, ibid.
An account of the great comet of 1680, ibid.
Comets proved to have no light but what they receive from theSun , 180.
Of the diameter, magnitude, distance, &c. of the comets, 180_
182.
The opinions of several eminent Astronomers respectin'* the tailsof comets, 184—189. 3
The near approach of some comets to the Sun , supposed to subjectthem to intense and inconceivable degrees of heat, 190.
The universal deluge attributed by Whiston to the near approachof a comet, 19J.
The analogy discovered by Kepler , between the periodic timesof the planets and their distances from the Sun , found to takeplace also in the comets, 192.
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