Miscellaneous Scientific Papers of the Allegheny Observatory, Volume 1 |
Common terms and phrases
aberration absorption accuracy Allegheny Observatory already angle angular aperture Annual Report Astronomical Astrophysical Journal axis Cepheid variables clock coefficient collimator complete concave grating considerable cos² curvature definition determined diffraction Director displacement eclipse edge effect equation error F. L. O. WADSWORTH field flint focal length focal plane focus FRANK SCHLESINGER glass heliometer heliostat increase instrument investigation Jour Keeler lens Lick Observatory light lines maximum measurement ment meridian circle method mirror mounting objective spectroscope observations obtained optical Phil photographic photospheric position prism train Professor Langley radiation ratio rays reflecting telescope refraction resolving power resolving-power S. P. Langley semi-angular aperture sin² slit spectral image spectrograph spectroscopic binaries spectrum spherical star surface Table telescope temperature tenth-meters tion tube values variation visual binaries Volume wave-front wave-length width Yerkes Observatory Δλ
Popular passages
Page 2 - I remember aright, he first told them that, incredible as it might seem, there was not only a time in the world's youth when the mushroom itself was young, but that the sun in those early ages was in the eastern, not in the western, sky. Since then, he explained, the eyes of scientific ephemera had followed it, and established by induction from vast experience the great
Page 2 - ... to say of the gloomy prospect. If I remember aright, he first told them that, incredible as it might seem, there was not only a time in the world's youth when the mushroom itself was young, but that the sun in those early ages was in the eastern, not the western, sky.
Page 2 - ... decline from that which saw it rise. Imagine the sun about to set, and the whole nation of mites gathered under the shadow of some mushroom (to them ancient as the sun itself...
Page 1 - ... of an inch nearer the mirror than those from its central parts. If, now, the converse experiment be tried, and a mirror of the same size and focal length, which can converge parallel rays falling on all its parts to one focus, be examined at the center of curvature, it gives there an amount of longitudinal aberration 10-100 of an inch, equal to twice the preceding.
Page 14 - Publications of Learned Societies and Periodicals in the Library of the Smithsonian Institution.
Page 10 - The corona is effectively cooler than the bolometer, and appears, therefore, neither to reflect much light from the Sun nor chiefly by virtue of a high temperature to give light of its own, but seems rather to be giving light in a manner not associated with a high temperature, or at least with the preponderance of infra-red rays usual in the spectra of hot bodies.
Page 3 - ... of Naval Research. There is no assured source for meeting the Board's future administrative expenses, although it is being called upon increasingly to furnish advice and assistance on both national and international problems concerned with science in the Pacific. Committee on Undersea Warfare.- — During the past year two new members have been added to the committee: Dr. Lyman Spitzer, Jr.. of Princeton University, and Dr. Harvey Brooks of the General Electric Co. Mr. TE Shea has resigned from...
Page 44 - ... Railway Time, by SPL; American Exchange and Review, 24, 271-276, Jan. 1874. *g. On the Minute Structure of the Solar Photosphere, by SPL; Am. Jour. Sci. (Ser. 3), 7, 87-102, Feb. 1874. *io. The External Aspects of the Sun, by SPL; Jour. Franklin Inst., 68, 123-134; 207-212, Aug. and Sept. 1874. *n. On the Comparison of Certain Theories of Solar Structure with Observation, by SPL; Am. Jour. Sci. (Ser. 3), 9, 192-198, Mar. 1875. Mem. Spettr. Ital., 4, 1-8, 1875. 12. Sur la Temperature relative...
Page 15 - speculation on this basis of perfectly gaseous stuff ought to cease when the density of the gas at the center of the star approaches one-tenth of the density of ordinary water in the laboratory." It is clear from the context that this refers rather to the beginning of sensible departures from Lane's Law than to the actual attainment of the maximum temperature, which would come later; and it seems probable, from the considerations already mentioned, that the maximum temperature of the surface would...