Institutes of Natural Philosophy: Theoretical and PracticalHilliard, Gray, Little, and Wilkins, 1832 - 216 σελίδες |
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altitude angle of incidence angle of refraction apparent diameter apparent magnitude appear apsis attraction axis body centre of gravity centrifugal force centripetal force circle colours concave conductor consequently converging convex convex lens degree denser medium described direction diurnal motion diverge earth ecliptic electric electrified equal equator fall fluid focus given glass greater Hence horizon imaginary radiant inches incident rays inclined inferior conjunction inferior planet inversely latitude length lens less magnet magnitude mercury meridian mirror moon moon's motion move nearer nodes object oblique observed orbit orifice parallax parallel rays particles passing perpendicular plane Plate pole pressure Prop proposition quantity of matter radius ratio refraction revolution revolve right ascension right line satellite SCHOL seen semidiameter side sine space specific gravity square stars subtend sun's supposed surface syzygies tangent telescope triangle tube velocity vessel weight whence
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Σελίδα ii - Co. of the said district have deposited in this office the title of a book, the right whereof they claim as proprietors, in the words following-, viz. " POEMS, by George Bancroft." In conformity to the act of the congress of the United States...
Σελίδα 172 - I perceive three volcanoes in different places of the dark part of the new moon. Two of them are either already nearly extinct, or otherwise in a state of going to break out; which, perhaps, may be decided next lunation. The third shews an actual eruption of fire, or luminous matter.
Σελίδα 35 - Quantities, and the ratios of quantities, which in any finite time converge continually to equality, and before the end of that time approach nearer to each other than by any given difference, become ultimately equal.
Σελίδα 130 - Every Ray of Light in its passage through any refracting Surface is put into a certain transient Constitution or State, which in the progress of the Ray returns at equal Intervals, and disposes the Ray at every return to be easily transmitted through the next refracting Surface, and between the returns to be easily reflected by it.
Σελίδα xiv - This may be very substantially answered by many proofs drawn from natural philosophy, which show that heat is produced by the sun's rays only when they act on a calorific medium ; they are the cause of the production of heat, by uniting with the matter of fire which is contained in the substances that are heated...
Σελίδα 209 - ... diameter. The star is perfectly in the centre, and the atmosphere is so diluted, faint, and equal throughout, that there can be no surmise of its consisting of stars ; nor can there be a doubt of the evident connection between the atmosphere and the star. Another star not much less in brightness, and in the same field of view with the above, was perfectly free from any such appearance.
Σελίδα 64 - As the undulatory motion of the air, which constitutes sound, is propagated in all directions from the sounding body, it will frequently happen that the air, in performing its vibrations, will impinge against various objects, which will reflect it back, and so cause new vibrations the contrary way ; now if the objects are so situated as to reflect a sufficient number of vibrations back, viz...
Σελίδα 102 - This amounts to the same with saying, that, in the case before us, the sine of the angle of incidence is to the sine of the angle of refraction in a given ratio.
Σελίδα 209 - I arrived at last to spots in which no trace of a star was to be discerned. But then the gradations to these latter were by such well-connected steps as left no room for doubt but that all these phenomena were equally occasioned by stars, variously dispersed in the immense expanse of the universe.
Σελίδα 172 - The appearance of what I have called the actual fire or eruption of a volcano, exactly resembled a small piece of burning charcoal, when it is covered by a Very thin coat of white ashes, which frequently adhere to it when it has been some time ignited ; and it had a degree of brightness, about as strong as that with which such a coal would be seen to glow in faint day-light.