Publications of the Astronomical Society of the Pacific, Volume 18Astronomical Society of the Pacific., 1906 |
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Page 21
... position with reference to them . TIME SIGNALS . In charge of Mr. CHARLES M. Olmsted . Each of the three expeditions was provided with a pendu lum , consisting of a rod and a heavy flat lead disk , which could be adjusted to one ...
... position with reference to them . TIME SIGNALS . In charge of Mr. CHARLES M. Olmsted . Each of the three expeditions was provided with a pendu lum , consisting of a rod and a heavy flat lead disk , which could be adjusted to one ...
Page 22
... positions from simple computations , and the final adjustments are readily made . The Sun's altitude at Alhama was 55 ° , and the center of the lens was 32 feet 8 inches € 9.96 meters above the center of the photographic plate . Ten ...
... positions from simple computations , and the final adjustments are readily made . The Sun's altitude at Alhama was 55 ° , and the center of the lens was 32 feet 8 inches € 9.96 meters above the center of the photographic plate . Ten ...
Page 25
... position . The exposing shutter was a simple flap of zinc directly in front of the sensitive plate . The mount- ing of the instrument was of sugar - pine wood , and it was supported upon timbers set in stone and cement . The spectro ...
... position . The exposing shutter was a simple flap of zinc directly in front of the sensitive plate . The mount- ing of the instrument was of sugar - pine wood , and it was supported upon timbers set in stone and cement . The spectro ...
Page 27
... this exposure the plate was fixed in position . This spectrograph also received its light from the Yerkes Observatory colostat mirror . ULTRA - VIOLET SPECTROGRAPH , WITH MOVING PLATE . In Astronomical Society of the Pacific . 27.
... this exposure the plate was fixed in position . This spectrograph also received its light from the Yerkes Observatory colostat mirror . ULTRA - VIOLET SPECTROGRAPH , WITH MOVING PLATE . In Astronomical Society of the Pacific . 27.
Page 28
... position at the observing station in the accompanying illustration . The Lick Observatory cœlostat , seen in the same photograph , carries a 12 - inch flat mirror by PETITDIDIER , as well as the Schroeder's- metal mirror . The exposures ...
... position at the observing station in the accompanying illustration . The Lick Observatory cœlostat , seen in the same photograph , carries a 12 - inch flat mirror by PETITDIDIER , as well as the Schroeder's- metal mirror . The exposures ...
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Common terms and phrases
Astronomical Society Astrophysical atom August binary bright BURCKHALTER C. D. PERRINE California comet Comet-Medal Committee computed CROCKER CUSHING December Director discovery disintegration distance double stars Earth earthquake eclipse error expedition exposures F. R. ZIEL flocculi focal length Hamilton HERMANN CARL VOGEL hour inches instruments investigation January July June Jupiter latitude Lick Observatory light lines magnitude mass measures method Mills Expedition Moon Mount Mount Hamilton nebula night November observations obtained orbit Pacific pairs papers parallax particles period phenomena photographs planet plates position preliminary tremor present Professor proper motion Publications R. G. AITKEN radial velocity radiation radio-active radium rays reflector refraction right ascension San Francisco satellite Saturn Secretary September Solar Observatory spectra spectrograph spectroheliograph spectroscopic spectroscopic binaries spectrum stellar substances sun-spots telescope temperature theory tion TOWNLEY Ukiah University variable variable stars variation velocity W. W. CAMPBELL WILLIAM ALVORD
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Page 220 - VIII. Fall of chimneys ; cracks in the walls of buildings. IX. Partial or total destruction of some buildings. X. Great disasters; overturning of rocks; fissures in the surface of the earth; mountain slides.
Page 118 - While I must leave to others an estimate of the importance of these conclusions, it seems to me that they have a very direct bearing on many, if not all, questions concerning the cosmogony. If, for example, the spiral is the form normally assumed by a contracting nebulous mass, the idea at once suggests itself that the solar system has been evolved from a spiral nebula, while the photographs show that the spiral nebula is not, as a rule, characterized by the simplicity attributed to the contracting...
Page 256 - Report of the Astronomer Royal to the Board of Visitors of the Royal Observatory, Greenwich, read at the Annual Visitation of the Royal Observatory, 1860, June 2; and Address of the Astronomer Royal to the Board of Visitors, 1860, May 12.
Page 64 - The total range of speed is but three one hundredths of a kilometer per second. An observer favorably situated in another system, provided with instruments enabling him to measure speeds with absolute accuracy, could detect this variation, and in time say that our sun is attended by planets. At present, terrestrial observers have not the power to measure such minute variations. As the accuracy attainable improves with experience, the proportional number of spectroscopic binaries discovered will undoubtedly...
Page 264 - BY GEORGE E. HALE, WALTER S. ADAMS, AND HENRY G. GALE In considering the characteristic features of the spectra of sunspots, three points especially attract attention: 1. The fact that certain lines in the spectrum of a given element are strengthened, while others are weakened; the remainder of the lines being unaffected. 2. The inclusion of all the strengthened lines within the visible spectrum, none of them occurring in the ultra-violet, and their predominance in the red, yellow, and green. 3....
Page 119 - ... directed in somewhat changing courses, and would be pulsatory in character, resulting in rather irregular and somewhat divided arms, and in a knotty distribution of the ejected matter along the arms. These knots must probably be more or less rotatory from inequalities of projection. It is thus conceived that a spiral nebula, having two dominant arms, opposite one another, each knotty from irregular pulsations, and rotatory, the knots probably also rotatory, and attended by subordinate knots and...
Page 198 - Earth's crust with a velocity of some 14km of which I shall speak presently, and communicate a sort of stress to the superincumbent surface layer of the Earth's crust in the region about the observing station; the latter being, in consequence, thrown into its own proper vibrations. In fact, the preliminary...
Page 74 - ... Sun above the horizon proved to be a very important factor, so that the focus changed much more rapidly near noon than early in the morning. From the outset, the advantages of observing the Sun during the early morning hours had been apparent. In view of the difficulties that were being experienced, this point was again carefully investigated, and it was soon found that with the Snow telescope the finest definition is to be expected about one hour after sunrise. At this time the mountain is but...
Page 120 - In the particular case of the solar nebula it is assumed (1) that the central mass was relatively very great; (2) that the knots were very irregular in size and placed at irregular distances from the center; and (3) that the nebulous portion was very small relative to the central mass and probably large relative to the knots.
Page 195 - The preliminary tremor, which consists of vibrations of small amplitude and of comparatively short period, is divided into the earlier portion or the first preliminary tremor, and the later portion or the second preliminary tremor. Commencement of the latter is market! by an increa.se of the amplitude, and, in many cases, also by the appearance of slow undulations. The principal portion...