Astronomical, Magnetic and Meteorological Observations Made at the United States Naval ObservatoryU.S. Government Printing Office, 1867 - Astronomy |
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Page xxxix - ... these statements to the attention of the department and of Congress. The work of this observatory, like that of the Greenwich Observatory, England, has always contemplated the direct relation between the highest astronomical results and the improvement of navigation. In England, the Astronomer Royal is directed by his warrant of office "to apply himself with the most exact care and diligence to the rectifying of the tables of the motions of the heavens and the places of the fixed stars, in order...
Page 465 - It is covered with a parallel plate of the same material, whose under surface and the rim of the bell have been ground smooth so as to prevent the passage of dust between them. There are two apertures in the cover, each of which is fitted with an ivory ferule cemented to the glass. The barometer tube passes freely, but not too loosely, through the larger and central one, and the extremity of the measuring apparatus is admitted through the smaller. The cistern is filled with mercury to within one-fourth...
Page xxiv - S being the sidereal time of observation, and a the right ascension of the Star. Table I contains the value of the second term (p cos A) or the first correction ; assuming, as mean values, p = 88
Page viii - There are substantial supports outside the rotunda, from one or the other of which all portions of the heavens may be seen, and a level platform covers the roof of the building for the greater convenience of the observer with the comet_seeker.
Page 519 - Map of Wisconsin, with Lines showing the Remarkable Effect of Lake Michigan in elevating the Mean Temperature of January, and depressing that of July.
Page viii - Communicating a report of the plan and construction of the depot of charts and instruments, with a description of the instruments, &c.
Page 411 - ... Gentleman's Diary, London, 162, 1865, p. 61. 40. Solar parallax, deduced from observations of Mars with equatorial instruments. Washington Obs'ns, 1863, Appendix A, pp. LX-LXIV. 41. New elements of Nemausa. Washington Obs'ns, 1863, Appendix B, pp. LXXXIII-XC. 42. Observations with the equatorial, 1863. Right ascensions and declinations of stars, asteroids and comets observed with the equatorial, 1863. [By James Ferguson and Asaph Hall. Professor Hall observed : comets 1863,1, 1863,11, 1863, IV;...
Page vii - The telescope and its counterpoise are outside of the supporting pier, but their weights are transferred to the bearing points of the Y's by levers and other counterpoises within the pivots and axis. Its pier is a wide monolith, whose central portion has been cut out for the accommodation of a reversing apparatus of special construction. The instrument has not been in use for several years, and such had been its neglect that it was...
Page v - Superintendent; two are filled with charts properly arranged for distribution to ships of the Navy, and the remainder on the first and second floors are assigned to the assistants. A etnndnnt clock by Kessels, and a standard barometer by Green, are mounted in the office of the Superintendent.
Page vii - The pier upon which the instrument is mounted is a wide monolith, whose central portion has been cut out for the accommodation of a reversing carriage of special construction. The clock for this room was made by Charles Frodsham, and is mounted against a granite pier placed to the east of the Prime Vertical Transit Instrument.