Astronomical Observatory of Harvard College: Miscellaneous PapersHarvard College, 1888 |
Common terms and phrases
accuracy Algol angle Argelander assumed Astron Astronomical Astronomische azimuths bands binary brighter brightness catalogue 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 fundamental stars Geminorum given Harvard College Observatory inch increase instrument interval L-L₁ L₁ large telescope last column latitude length light curve lines logarithms longitude Lyræ M₁ magnitude mean Meridian Circle meridian photometer meter method Mètre micrometer microscope minima minimum minutes motion nearly nebula objects obtained orbit period photometric photometric measures PICKERING plane planetary nebula plate position precision present probable error proper motion reduced Report residuals right ascension satellite scale Schmidt Schönfeld screw spectra standard stellar magnitude systematic errors Table temperature tenths tion Uranometria variable stars variation in light yard zone
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Page 273 - ... the reader is referred to the references at the end of this chapter for further information.
Page 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...
Page 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.
Page 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.
Page 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...
Page 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.
Page 3 - 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°.
Page 308 - Narrative of the Origin and Formation of the International Association for obtaining a Uniform Decimal System of Measures, Weights, and Coins.
Page 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.
Page 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.