Astronomical Observatory of Harvard College: Miscellaneous PapersHarvard College, 1888 |
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Halaman 217
... telescope , or from a telescope with- out an observer . The true patron of science will select an object proportionate to his gift . If he will abundantly endow any one subject , no matter how limited , he will confer a real boon on his ...
... telescope , or from a telescope with- out an observer . The true patron of science will select an object proportionate to his gift . If he will abundantly endow any one subject , no matter how limited , he will confer a real boon on his ...
Halaman 223
... TELESCOPE AND THE MICROSCOPE . BY PROFESSOR WILLIAM A. ROGERS . Presented Oct. 9 , 1878 . Ir is often desirable in astronomical observations to assign to a given result the degree of precision which the observations will justify ...
... TELESCOPE AND THE MICROSCOPE . BY PROFESSOR WILLIAM A. ROGERS . Presented Oct. 9 , 1878 . Ir is often desirable in astronomical observations to assign to a given result the degree of precision which the observations will justify ...
Halaman 225
... telescope , the separate values are simple functions of the quantity required , and involve only the accidental errors of the observer , either in making the bisections of the divisions of the circle , or in reading the index of the ...
... telescope , the separate values are simple functions of the quantity required , and involve only the accidental errors of the observer , either in making the bisections of the divisions of the circle , or in reading the index of the ...
Halaman 230
... telescope . By alternating between bright and faint images of the same star , on different groups of the transit threads , the personal equation between bright and faint stars can be found . This plan was followed in the investigation ...
... telescope . By alternating between bright and faint images of the same star , on different groups of the transit threads , the personal equation between bright and faint stars can be found . This plan was followed in the investigation ...
Halaman 231
... telescope for the last forty years , if we except the tentative investigations of the last five or six years . Argelander's Åbo Catalogue of 1830 , and the Pulkowa Catalogue of 1845 , are as yet pre - eminent for that kind of accuracy ...
... telescope for the last forty years , if we except the tentative investigations of the last five or six years . Argelander's Åbo Catalogue of 1830 , and the Pulkowa Catalogue of 1845 , are as yet pre - eminent for that kind of accuracy ...
Istilah dan frasa umum
Accumulated Errors accuracy Algol angle Argelander assumed Astron Astronomical bands binary star brighter brightness catalogue centimeter Cephei Coast Survey column gives Comet compared comparison stars computed correction corresponding determined diameter difference distance double stars Durchmusterung eclipse ephemeris equal equation equatorial estimate faint fainter formula Geminorum given Harvard College Observatory inch increase instrument interval L₁ large telescope last column latitude length light curve logarithms longitude Lyræ magnitude mean meridian circle meridian photometer meter method micrometer microscope minima minimum minutes motion nearly nebulæ objects obtained orbit parallax period Persei PICKERING placed plane plate position precision present probable error Proc Professor proper motion reduced Report residuals right ascension satellite scale Schmidt Schönfeld Science screw space spectra standard stellar magnitude systematic errors Table temperature tenths tion Uranometria variable stars variation in light W. A. ROGERS yard zone
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Halaman 273 - ... the reader is referred to the references at the end of this chapter for further information.
Halaman 274 - Yard 1760" are engraved, shall be, and the same is hereby declared to be, the original and genuine standard of that measure of length or lineal extension called a yard ; and that the same straight line or distance between the centres of the said two points in the said gold studs in the said brass rod, the brass being at the temperature of 62 ° of Fahrenheit's thermometer, shall be and is hereby denominated the "Imperial Standard yard...
Halaman 310 - LENGTH-COMPARISONS of the STANDARDS of LENGTH of England, France, Belgium, Prussia, Russia, India, Australia, made at the Ordnance Survey Office, Southampton, by Captain AR CLARKE, RE, FRS, under the direction of Major-General Sir HENRY JAMES, RE, FRS, &c., Cor.
Halaman 311 - Sess. (1818-10), vol. vi., Doc. 109. Report on Weights and Measures, by JQ Adams, Sec. of State (Feb. 22, 1821). Executive Papers, 16th Cong., 2d Sess., Doc. 109. Report of Committee to whom was referred the Report of the Sec. of State. Reports of Committees, 17th Cong., 1st Sess. (1821-22), vol. ii., Doc. 65. Comparison of Weights and Measures of Length and Capacity, by FR Hassler.
Halaman 2 - Attach a microscope first to one end and then to the other end of the planer, and make the adjustment for level such that the surface of the mercury is sharply in focus under the microscope in the two positions. The bed-plate can then be blocked up at the intermediate points until every point is in focus. With regard to...
Halaman 24 - Lyree, ijAquilce, and 8 Cephei, have been observed with great care, so that their variations are known with much precision. Each will therefore be discussed in turn, according to the following method. As the variation is periodic, it will be convenient to denote the time by an angle, v, such that 360° shall correspond to one period or revolution of the star. We now wish the light * Poggendorff's Annalen, xxxiii.
Halaman 5 - Bache telescope has been employed. The third research relates to a more careful study of the spectra of the brightest stars. For this work Mrs. Draper has lent the 11-inch photographic lens employed by her husband. .She has also furnished an admirable mounting for the instrument, and a small observatory to contain it. Two prisms have been constructed to place in front of the object-glass, the large one having a clear aperture of eleven inches square, and an angle of nearly 15°.
Halaman 308 - Narrative of the Origin and Formation of the International Association for obtaining a Uniform Decimal System of Measures, Weights, and Coins.
Halaman 21 - Lyrce and 8 Cephei. V. Stars which every few days undergo for a few hours a remarkable diminution in light, this phenomenon recurring with great regularity. Examples, /3 Persei and S Cancri.
Halaman 312 - Commissioners appointed to consider the Steps to be taken for the Restoration of the Standards of Weight and Measure, by Airy, Baily, Bethune, Herschel, Lefevre, Lubbock, Peacock, and Sheepshanks.