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action angular diameter Apennines appear Aristarchus astronomer axial rotation body bright streaks cause central cone centre CHAPTER chasms circular colour comparatively condition consider conspicuous cooling Copernicus cracks crust degree density detected distance earth eclipse effect ejected eruption evidence examples existence expansion feet fluid force formation full moon gravity heat hemisphere Herodotus igneous illuminated illustration infer lava libration light lunar atmosphere lunar craters lunar globe lunar surface mass material minute molten matter moon's surface motion Nasmyth nearly nebula nebulŠ nebular hypothesis object observed orbital revolution parallax peaks phenomena planetary planets Plate plateau Plato portion present produced Ptolemy radiating rampart rays refer regard regions remarkable result ridges satellite seen shadow side small craters solar solid solidified sphere spots stars summit suppose surrounding telescope temperature terrestrial tion Tycho vapour vast vent Vesuvius visible volcanic volcanic crater weight Woodburytype zodiacal light
Page 11 - Heat is a very brisk agitation of the insensible parts of the object, which produces in us that sensation from whence we denominate the object hot ; so what in our sensation is heat, in the object is nothing but motion.
Page 8 - that every particle of matter in the universe attracts every other particle, with a force whose direction is that of the line joining the two, and whose magnitude is directly as the product of their masses, and inversely as the square of their distances from each other.
Page 8 - The law of gravitation states that the force of gravitation is directly proportional to the mass, and inversely proportional to the square of the distance.
Page 13 - foot-pound " has been introduced to express in a convenient way the lifting of one pound to the height of a foot. Thus, the quantity of heat necessary to raise the temperature of a pound of water one degree Fahrenheit being taken as a standard, 772 foot-pounds constitute what is called the mechanical equivalent of heat.
Page 14 - Newton's theory of gravitation, whilst it enables us to determine, from its present form, the earth's state of aggregation in ages past, at the same time points out to us a source of heat powerful enough to produce such a state of aggregation, powerful enough to melt worlds ; it teaches us to consider the molten state of a planet as the result of the mechanical union of cosmical masses, and thus to derive the radiation of the sun and. the heat in the bowels of the earth from a common origin.
Page 2 - ... occur to any one who has not before him the result of the critical examination of the nebulous system which has been displayed in this paper. The end I have had in view, by arranging my observations in the order in which they have been placed, has been to show, that the above mentioned extremes may be connected by such nearly allied intermediate steps, as will make it highly probable that every succeeding state of the nebulous matter...
Page 13 - He also urged water through capillary tubes, and determined the amount of heat generated by the friction of the liquid against the sides of the tubes. And the results of his experiments leave no shadow of doubt upon the mind that, under all circumstances, the quantity of heat generated by the same amount of force is fixed and invariable.
Page 2 - The total dissimilitude between the appearance of a diffusion of the nebulous matter and of a star, is so striking, that an idea of the conversion of the one into the other can hardly occur to any one who has not before him the result of the critical examination of the nebulous system which has been displayed in this paper. The end I have had in view, by arranging my observations in the order in which they have been placed, has been to...
Page 13 - ... its moving force destroyed by collision with the earth. Conversely, the amount of heat necessary to raise a pound of water one degree in temperature...
Page 2 - The end I have had in view, by arranging my observations in the order in which they have been placed, has been to show, that the above-mentioned extremes may be connected by such nearly allied intermediate steps, as will make it highly probable that every succeeding state of the nebulous matter is the result of the action of gravitation upon it while in a foregoing one, and by such steps the successive condensation of it has been brought up to the planetary condition.