The SunD. Appleton, 1881 - 321 páginas |
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Términos y frases comunes
absorption actinometer amount of heat Ångstrom appear astronomers BALFOUR STEWART Bolometer bright lines bright-line spectrum brilliant cent chromosphere clouds collimator color corona course curve dark lines deduced density determine diameter diffraction diffraction grating disk distance disturbance earth earth's atmosphere eclipse edge element eruptions eyepiece fact faculæ Faye filaments Fraunhofer lines gaseous gases Herschel hundred hydrogen incandescent inch instrument intensity Langley latitude less light limb liquid Lockyer luminous magnetic mass matter means measure metal meteoric method metres minute moon motion nearly object-glass observations orbit ordinary penum penumbra period phenomena photographic photosphere planet portion precisely present prism probably produced Professor prominences protuberances radiation rays rotation Secchi seen slit solar atmosphere solar constant solar parallax solar spectrum solar surface spectra spectroscope sphere spots substance sun-spot sun's surface sunlight telescope temperature terrestrial theory thousand miles tion umbra vapors velocity visible whole
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Página 295 - TEXT-BOOKS OF SCIENCE ADAPTED FOR THE USE OF ARTISANS AND STUDENTS IN PUBLIC AND SCIENCE SCHOOLS...
Página 296 - ... never before published. Their efforts have in all cases tended to simplify the subjects treated, to avoid technicalities, and so to render all that Is presented easily understood by the general reader as well as by the mechanical student.
Página 296 - The attempt at a connected account of the General Physiolojry of Muscles and Nerves is, as far as I know, the first of its kind. The general data...
Página 254 - ... forty-six thousand years. A quantity of matter equal to only about one one-hundredth of the mass of the earth, falling annually upon the solar surface, would, therefore, maintain its radiation indefinitely. Of course, this increase of the sun would cause an acceleration of the motion of all the planets — a shortening of their periods. Since, however, the mass of the sun is three hundred and thirty thousand times that of the earth, the yearly addition would be only one thirty -three-millionth...
Página 115 - ... the other parts of the luminous margin too are pressing, diminishing, and finally overcasting the whole, — thus ending the ephemeral existence of the spot. Rather a good chance is required for observing the remarkable phenomenon which introduces the covering process, since it is achieved in a few minutes, and it demands, moreover, a perfectly calm atmosphere, in order not to be confounded with a kind of scintillation, which is perceived very often in the spots, especially with fatigued eyes....
Página 166 - ... western side, where the sun was just coming out, a long and very narrow streak of a dusky, but strong red light, seemed to colour the dark edge of the moon, though nothing like it had been seen immediately after the emersion. But this instantly vanished upon the first appearance of the sun, as did also the aforesaid luminous ring.
Página 296 - American practice in the mechanical arts, and compares the same with that of other nations. It also exhibits the extent to which American invention and discovery have contributed to the world's progress during the last quarter century. The contributors include many of the most eminent American mechanical experts and engineers.
Página 237 - Or, to put it differently, if we could build up a solid column of ice from the earth to the sun, two miles and a quarter in diameter,- spanning the inconceivable abyss of...