This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1816 Excerpt: ...where the sun.--If the second place lies under any of the meridians marked on the globe, the mark with the pencil may be left out, as the meridian answers the same purpose. t Astronomers have divided the face, or disc, of the snn and moon into twelve eqoal parts, called digits, by which the quantity of an eclipse is ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1816 Excerpt: ...where the sun.--If the second place lies under any of the meridians marked on the globe, the mark with the pencil may be left out, as the meridian answers the same purpose. t Astronomers have divided the face, or disc, of the snn and moon into twelve eqoal parts, called digits, by which the quantity of an eclipse is chiefly specified. will be vertical at the time when the eclipse begins; rectify the globe for the antipodes of that place, keeping the place at the meridian, and set the index to the upper XII, turn the globe until it points to the under XII, then all those places above the horizon will have the eclipse visible. Given an eclipse of the moon, the 22d of July, 3 ho. 25 mi. P. M.; required at what place it will be visible? Answer, at New Holland, over the most art of Asia, the east part of Africa, the Indian Ocean, &c. Given an eclipse of the moon, the 20th of March, at 10 ho. P. M.; required what places will have it visible? Answer, the east part of America, the Atlantic and Indian Oceans, Europe, Africa, and the most part of Asia. Eclipses of the moon are seen from all parts of that hemisphere of the earth which is next to her, and are equally great to each of those parts; hut the sun's eclipses are visible only to that small portion of the hemisphere next to him, whereon the moon's shadow falls; the moon's dark shadow covering only a spot on the earth's surface, about 180 miles broad, when her diameter appears largest and the sun's the least, and the total darkness can extend no farther than the dark shadow oovers. PROBLEM XXXIX. The day of the month and hour that a solar eclipse begins, of not less than eight or nine digits, being given, to find the places where it is visible. Find the place where the sun will be vertical at the given time...
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