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. 1914 Excerpt: ...unaided eye at Mantoloking, N. J., 3h 35m A. M., E. s. T., Tuesday, July 21, 1908 ( 57, Obs.). Required the coordinates from the Ephemeris for this time. Since the values sought are to be found in the Greenwich section of the Ephemeris ( 34), the time of observation must first be expressed in the time used there. ...
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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. 1914 Excerpt: ...unaided eye at Mantoloking, N. J., 3h 35m A. M., E. s. T., Tuesday, July 21, 1908 ( 57, Obs.). Required the coordinates from the Ephemeris for this time. Since the values sought are to be found in the Greenwich section of the Ephemeris ( 34), the time of observation must first be expressed in the time used there. According to 35, the astronomical date is 15h 35m, July 20, and by 48, the Greenwich time is 5h hours later or 20h 35m, so the coordinates are to be taken out for a time 0h.4 before 21h, as it is the rule in interpolating, to work always from the function nearest that required. The moon's right ascension and declination for 20 and 21 hours, from p. 118 of the Ephemeris are, July 20, 20h, 3's R. A., 2h 30m; 3's Decl., +10.2 ""21, 3'sR. A., 2 32;3's Decl., +10.4 In one hour, therefore, the change in R. A. is 2m, and in Decl., 0.2, and 0.4 of these differences subtracted from the values opposite 21h, gives the required coordinates of the moon, July 20, 20h 35m, R. A., 2h 31m; and Decl., +10.3 Exercise 3.--The following positions for Halley's Comet, 1910, are taken from Dr. Smart's Ephemeris, computed for 9h Greenwich time. (Journal, British Ast. Ass., Vol. XX, No. 6): May 23, R. A., 7h 58m.O; Decl., + 11 40' May 24, R. A., 8 26.4; Decl., + 9 33 Required the coordinates of the comet at 8h.5 p. M., C. S. T., May 23, 1910. The time, 8h.5 p. M., for which the coordinates are desired, equals 14h.5, Greenwich time ( 48), and so is 5h.5 later than that for which the Ephemeris is given. Since the change in right ascension in 24h is 28m.4, and in Decl. 2 7', j of these differences are to be combined with the Ephemeris values for May 23, fixing the comet's place in, R. A., 8h 4m.5, and Decl., + 11 11'. When final results are...
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Seller's Description:
Near Fine. First edition. Octavo. 126pp. Flexible green cloth over boards gilt. Previous owner's name front fly, lightly rubbed, near fine. Textbook by an important early female astronomer. Byrd was an active participant in the co-education movement, she also taught at Smith and Carleton Colleges. She resigned from Smith in protest over their ties to both Carnegie and Rockefeller.