Memoirs of the Royal Astronomical Society, Volume 36; Volumes 1866-1867Priestley and Weale, 1867 |
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Common terms and phrases
1st mag Aldebaran angle aperture appeared Astronomer Royal atmosphere axis bright lines calculated Catalogue centre CHARLES PRITCHARD clouds colour comet conjunction with following conjunction with preceding Corona crater dark determined diameter Dione direction disk distance Ditto ditto Ditto double stars Earth Enceladus Equatoreal error eye-piece faint following edge glass Gold Medal Greenwich Herschel Huggins inches instrument John Herschel Jupiter Leonis light limb Linné longitude magnitude Mars mean measures Meteoric Shower micrometer minute Monthly Notices Moon Moon's motion nearly Nebula number of meteors object object-glass observations obtained orbit Orionis Otto Struve Perihelion planet position preceding edge prism Professor proper motions radiant point remarkable Rhea Right Ascension ring Royal Observatory satellites seen Sirius Society Solar Eclipse spectra spectrum spot stell Sun's telescope Tethys tion Ursa visible W. R. Dawes
Popular passages
Page 113 - All these facts are comprehended in the statement that in a constant temperature the absorption of a particle is equal to its radiation, and that for every description of light. It was also noticed that all coloured glasses ultimately lose their colour in the fire as they approach in temperature the coals around them, the explanation being, that while red glass, for instance, gives out a greenish light, it passes red light from the coals behind it, while it absorbs the green...
Page 110 - The light of the star is compound, and has emanated from two different sources. Each light forms its own spectrum. In the instrument these spectra appear superposed. The principal spectrum is analogous to that of the sun, and is evidently formed by the light of an incandescent solid or liquid photosphere, which has suffered absorption by the vapours of an envelope cooler than itself. The second spectrum consists of a few bright lines, which indicate that the light by which it is formed was emitted...
Page 117 - That these lines were not produced by the portion of the earth's atmosphere through which the light of Mars had passed, was shown by the absence of similar lines in the spectrum of the moon, which, at-the time of observation, had a smaller altitude than Mars.
Page 109 - This observation was sufficient to solve the long-agitated inquiry in reference to this object at least, and to show that it was not a group of stars, but a true nebula. A spectrum of this character, so far as our knowledge at present extends, can be produced only by light which has emanated from matter in the state of gas.
Page 118 - ... with particular portions of the planetary surface. The evidence we possess at present appears to support the opinion that the planet's distinctive colour has its origin in the material of which some parts of its surface are composed. Mr. Lockyer's observation, that the colour is most intense when the planet's atmosphere is free from clouds, obviously admits of an interpretation in accordance with this view.
Page 113 - ... have its temperature raised by light from the source, of the precise quality in question. In the atmosphere around the sun, therefore, there must be present vapour of sodium, which, according to the mechanical explanation thus suggested, being particularly opake for light of that quality, prevents such of it as is emitted from the sun from penetrating to any considerable distance through the surrounding atmosphere.
Page 108 - ... and map them all, the labour of months would barely suffice. The physical result of all this scrupulous and conscientious care was to discover the fact, or it may be to confirm the suspicion, that those mysterious lights with which the firmament is spangled, are in strict reality worlds fashioned in their material constitution, at least not altogether differently from the fashion of the little orb on which we live ; beyond the question of a doubt they are proved by the investigations of our Medallists...
Page 109 - ... all constructed upon the same plan as our sun, and are composed of matter identical, at least in part, with the materials of our system. " The differences which exist between the stars are of the lower order of differences of particular adaptation, or special modification, and not differences of the higher order of distinct plans of structure. " There is, therefore, a probability that these stars, which are analogous to our sun in structure, fulfil an analogous purpose, and are, like our sun,...