 | Henry Raper - 1840 - 700 σελίδες
...difference, or the combined effect of parallax and refraction, is called the Correction of Altitude. 334. The SEMI-DIAMETER of a celestial body is half the...angle subtended by the diameter of the visible disc. It is evident that the semi-diameter will be greater as the body is nearer, and smaller as it is further... | |
 | Janet Taylor - 1851 - 674 σελίδες
...the apparent altitude, but as seen from the centre the true altitude. The semidiameter of an object is half the angle subtended by the diameter of the visible disc. Augmentation. Since the moon is nearer to an observer on the earth, when she is in the zenith than... | |
 | Henry Raper - 1870 - 968 σελίδες
...quantities is the diff. between the true and apparent altitudes. This difference, or the combined efi'ect of parallax and refraction, is called the Correction...from S to D and F ; the half of this angle is DSC or CS F. and is called the semi-diameter. It is evident that the semi-diameter will be greater as the... | |
 | John Bradley Harbord - 1883 - 472 σελίδες
...fipi-, which we find in Aemz'sphere, ftemicycle, etc. Semidiameter. — The semidiameter of a heavenly body is half the angle subtended by the diameter of the visible disc at the eye of the observer. For the same body the semidiameter varies with the distance ; thus the... | |
 | Nathaniel Bowditch - 1888 - 704 σελίδες
...being the same as was found by the table. SEMI-DIAMETER. Art. 235. The semi-diameter of a heavenly body is half the angle subtended by the diameter of the visible disc at the eye of the observer. For the same body the semi-diameter varies with the distance ; thus, the... | |
 | American School (Chicago, Ill.) - 1903 - 390 σελίδες
...Fig. 10. parallax an additive correction, which is the angle BSO, and is given in Table 16, Bowditch. Semidiameter of a celestial body is half the angle subtended by the body's diameter. This is an additive correction if the lower limb is used, and gives the altitude of... | |
 | Royal Geographical Society (Great Britain) - 1906 - 514 σελίδες
...par., is too great for any other latitude. The reduction is given in Table XVIII. The Semi- Diameter of a celestial body is half the angle subtended by the diameter of the visible disc. It is evident that the semi-diameter will be greater as the body is nearer, and smaller as it is farther... | |
 | 1906 - 680 σελίδες
...Fig. 19. parallax an additive correction, which is the angle BSO, and is given in Table 16, Bowditch. Semidiameter of a celestial body is half the angle subtended by the body's diameter. This is an ( additive correction if the lower limb is used, and gives the altitude... | |
 | Nathaniel Bowditch - 1906 - 670 σελίδες
...in entering Table 24 for parallax and refraction. SEMIDIAMETEB. 3O7. Tho bemidiameter of a heavenly body is half the angle subtended by the diameter of the visible disk at the eye of the observer. For the same body the semidiameter varies with the distance; thus,... | |
 | Nathaniel Bowditch - 1916 - 912 σελίδες
...in entering Table 24 for parallax and refraction. SEMIDIAMETER. 307. The semidiameter of a heavenly body is half the angle subtended by the diameter of the visible disk at the eye of the observer. For the same body the semidiameter varies with the distance; thus,... | |
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For the same body the semidiameter varies with the distance; thus, the difference of the sun's semidiameter at different times of the year is due to the change of the earth's distance from the sun; and similarly for the moon and the planets. 
