The Astrophysical Journal, Volume 7University of Chicago Press, 1898 "Letters to the Editor" issued as Part 2 and separately paged from v. 148, 1967. Beginning in 2009, the Letters published only online. |
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absorption angle angular aperture aperture astronomical ASTROPHYSICAL JOURNAL atmosphere axis brighter Character Intensity Character Wave-length Intensity comparison computed corrected corresponding curve density determined Difference Micrometer reading disk displacement Earth Earth's atmosphere equation error exposure faculæ fainter field focal length gases Geissler tubes Harvard College Observatory heliographic helium hydrogen lines Intensity and Character Intensity Wave-length investigation Lick Observatory light limb Lord Rayleigh luminous magnetic magnitude measures meridian Micrometer reading Standard Milky mirror molecules nebulæ number of stars observations Observatory obtained paper period photographic photometric plane plate prime meridian prism Professor radiation ratio reading Standard Difference right ascension rotation scale solar spectra spectroscopic spectrum spots Standard Difference Micrometer stellar Sun-spots Sun's surface telescope temperature theory tion VANADIUM variable variable stars vibration visual Wave-length and Character Wave-length uncorrected Yerkes Observatory zone ΙΟ
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Pagina 73 - If the Theory of making Telescopes could at length be fully brought into practice, yet there would be certain Bounds beyond which Telescopes could not perform. For the Air through which we look upon the Stars, is in a perpetual Tremor; as may be seen by the tremulous Motion of Shadows cast from high Towers, and by the twinkling of the fix'd stars. The only remedy is a most serene and quiet Air, such as may perhaps be found on the tops of the highest Mountains above the grosser Clouds.
Pagina 153 - There is one circumstance which suggests doubts whether the analogue of radiating bodies is to be sought at all in ordinary mechanical or acoustical systems vibrating about equilibrium. For the latter, even when gyratory terms are admitted, give rise to equations involving the square of the frequency ; and it is only in certain exceptional cases, eg (31), that the frequency itself can be simply expressed. On the...
Pagina 302 - The quantity of sky light available varies tremendously with the weather, with the time of day, and with the season of the year.
Pagina 79 - Note on an Error in the Expression for the Intensity of Illumination at the Focal Plane of a Telescope due to an Infinitely Extended Luminous Area.
Pagina 73 - ... certain bounds beyond which telescopes could not perform. For the air through whIch we look upon the stars is in a perpetual tremor, as may be seen by the tremulous motion of shadows cast from high towers and by the twinkling of the fixed stars. The only remedy is a most serene and quiet air, such as may perhaps be found on the tops of the highest mountains above the grosser clouds.
Pagina 31 - The velocity whose square is the mean of the squares of the velocities of the individual molecules of a gas- — "the velocity of mean square...
Pagina 224 - P. JAERISCH. Theorie der Reflexion und Brechung transversaler Kugelwellen mit Anwendung auf die Reflexion und Brechung des Lichtes.
Pagina 224 - Further Note on the Influence of a Magnetic Field on Radiation Frequency.
Pagina 80 - On the Conditions Required for Attaining Maximum Accuracy in the Determination of Specific Heat by the Method of Mixtures.
Pagina 131 - The relative intensity of the components varies for different substances and for different lines of the same substance ; and accordingly the group may appear as a single line or a double or a triple. 3. The " outer lines " are nnsymmetrical, but are symmetrically placed with respect to the "middle line.