Analysis of a course of lectures on natural and experimental philosophy : viz. 1. Properties of matter, 2. Mechanics, 3. Chemistry, 4 and 5. Pneumatics, 6. Hydrostatics, 7. Electricity, 8. Electricity [sic], 9. Optics, 10. Use of the globes, &c., 11 and 12. Astronomy / by A. Walker.

  • Walker, A. (Adam), 1730 or 1731-1821.
Date:
[1795?]
Catalogue details

Licence: Public Domain Mark

Credit: Analysis of a course of lectures on natural and experimental philosophy : viz. 1. Properties of matter, 2. Mechanics, 3. Chemistry, 4 and 5. Pneumatics, 6. Hydrostatics, 7. Electricity, 8. Electricity [sic], 9. Optics, 10. Use of the globes, &c., 11 and 12. Astronomy / by A. Walker. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    [ «4 ] the opportunity of calculating the fun’s parallax, viz. 7 40' and of confequence his diflance, as well as that of the planets. The earth is the next planet in the order of the lyftem. Mars, fllll higher in the fyftem, is 167 millions of miles diflant from the fun, moves at the rate of 47,000 jniles an hour, goes round the fun in 678 days, and turns round on his axis* in 23 hours 39 minutes and 22 feconds, at a medium, according to Dr. Herfchel’s ob- fervations on a fpot on the face of Mars; though he obferves his motion not to be regular. He is about one- fifth as large as our earth; his red appearance is fuppofed to be occafioned by a grofs thick atmofphere with which he is furrounded, and which is fuppofed to fupply hi§ want of a moon. Jupiter, the largeft of the planets, is 570 millions of miles diftant from the fun, and above 400 millions from our orbit; he moves round the fun in about 12 years of our time, at the rate of 30,000 miles per hour; he is near 90,000 miles in diameter (/. e. near 1000 times as large as our earth) is accompanied by four moons, feme bigger and fome lefs than the earth, which revolve round him as our moon does round us; and the faint fubftances on his face, called his belts, are fuppofed to be parts of his atmofphere drawn into lines by his exceeding quick revolution on his axis, which is once in 9 hours 49 minutes. » Saturn, the fecond in magnitude, and hitherto confi- dered the moft diftant of all the planets, is 949 millions of miles from the fun ; near 70,000 miles diameter; moves at the rate of 18,000 miles an hour, but is too . remote for his fpots to be feen. He is equipt with five moons, (Dr. Herfchel has feen two more) beftdes a broad luminous ring which alfo refledls the fun’s light ftrongly