Elements of Astronomy for the Use of Schools and Academies; With Questions (Paperback)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: Sect. 6. Of Mart. 27. Next to the earth is the planet Mars. It revolves in its orbit/fn little less than two years/at the distance ofl44 millions of miles from the sun; and turns on i'ts axis in little less than 25 hours.' The light reflected by Mars is remarkably red. Spots and sometimes belts have been seen on the disk of this planet, some of which are permanent and others variable. These variations are supposed to arise from clouds and vapours floating in the atmosphere. The degree of heat and light at Mars is something less than one half what we enjoy. Sect. 7. Of Vesta, Juno, Pallas and Ceres. 28. Next to Mars in the solar system is Vesta. It was discovered by Dr. Olbers, of Bremen/ March 29, 1807. Its light is pure and white; and renders the planet visible to the naked eye. It revolves round the sun at the mean distance of about 223 millions of miles, /'in about 3 years and 8 months. The time of turning on its axis is not known. 29. Juno, the planet next to Vesta, was discovered .by Mr. Harding near Bremen, September 1, 1804. Its colour is red, and its atmosphere appears cloudy. Its mean distance from the sun is about 253 millions of miles.' Its orbit is very elliptical; so that its greatest distance from the sun is nearly double its least distance, and the time of passing through one half its orbit is about double the time of passing through the other half. It completes its revolution in about 4 years and 4 months, and is supposed to turn on its axis in about 27 hours. 30. Pallas was discovered by Dr. Olbersj' Marcfi 28, 1S02. It appears to have a dense cloudy atmosphere. It revolves round the sun in an orbit nearly as elliptical as that of Juno/in about 4 years and 7 months 4. the mean distance ol 263 millions of miles,7 The time of turning on its axis...