Astronomy and Astro-physics, Volume 5

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Carleton College Observatory, 1885
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Pagina 84 - A mere variation of shade does not alter the fixation of color, and we imagine it does not require a very great stretch of the imagination to conceive a shade which, in contradistinction to white or grey, may be called black opacity.
Pagina 257 - Threat'ning the world with famine, plague, and war ; To princes, death ; to kingdoms, many crosses ; To all estates, inevitable losses ; To herdsmen, rot ; to ploughmen, hapless seasons ; To sailors, storms ; to cities, civil treasons.
Pagina 37 - ... of the primary. The Integrals of these equations introduce six arbitrary constants of integration, which, when known, will completely determine the undisturbed motion of m relative to the sun. If we multiply the first of these equations by y, and the second by x, and subtract the last product from the first, we shall find, by integrating the result, xdy — ydx _ ~dt~ = 0> c being an arbitrary constant.
Pagina 164 - ... observing key, so as to leave a blank space of any desired amount between the records for different stars or groups of wires. The paper fillet is two inches in width, and the spool will hold about forty feet — sufficient for 1200 observations, including the spacing for different objects. The type are inked by means of small rollers covered with cloth, resting against their rim, and revolving with the wheel by friction. These rollers require inking every two or three days. The inking rollers,...
Pagina 158 - A Popular History of Astronomy during the Nineteenth Century. By Agnes M. Clerke. Third Edition. (London : A. and C. Black, 1893.) DURING the six years that have elapsed since the publication of the second edition of Miss Clerke's classical history of astronomy, new light has been thrown upon a number of old ideas, and many important discoveries have been made. It became necessary...
Pagina 202 - THE Lick Trustees have decided to purchase from Messrs. Feil and Mantois a 36-inch crown disk, which was made by them at the same time with the crown disk of the objective now in the hands of the Clarks. The Clarks "have received the order to figure this disk as a third (photographic) lens for the large objective.
Pagina 32 - Weekly newspaper devoted to science, mechanics, engineering discoveries, inventions and patents ever published. Every number illustrated with splendid engravings. This publication furnishes a most valuable encyclopedia of information which no person should be without.
Pagina 163 - ... one, two, or parts of two numbers being always printed, so that hundredths of seconds may be indicated. This train is primarily regulated to move uniformly by the Prauenhaufer friction balls, and secondarily by an electromagnet acting on the type-wheel and controlled by the standard clock.
Pagina 15 - XX/'HEN it became clearly understood that vision was *" not an immediate perception of objects by the eye, but was produced by the passage of an entity called light from the object to the eye, the question of the time which might possibly be required for this passage became one of interest to physical investigators. The first proposal for an experimental investigation of this question is due to Galileo.
Pagina 32 - This publication furn1shes a most valuable encyclopedia of information which no person should be without. The popularity of the SCIENTIFIC AMERICAN ia such that its circulation nearly equals that of all other papers of its class combined.

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