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action altitudes apparatus appears attraction Baily balance ball bodies Bouguer calculated called carried cause Cavendish centre compared considered corrections deflection determine diameter difference diminished direction distance divisions draw the arm drawn earth effect equal error exactly experiments Extreme points final force given gives globe gravity greater half hill inches increase iron Jupiter latitude lead length less lower magnetic manner masses mean density measure ment method middle midway motion mountain moved nature nearly necessary negative observations pendulum period placed planets point of rest position positive position Poynting produce proportion published Quito radius ratio referred Reich remarks scale sea-level seems side sphere square stars station suppose surface suspended taken temperature theory tion toises variation vertical vibration weights Weights moved whole wire
الصفحة 14 - ... while they were yet in fluid masses, all the heavier matter subsided to the centre. Since, therefore, the common matter of our earth on the surface thereof is about twice as heavy as water, and a little lower, in mines, is found about three, or four, or even five times more heavy, it is probable that the quantity of the whole matter of the earth may be five or six times greater than if it consisted all of water; especially since I have before shewed that the earth is about four times more dense...
الصفحة 16 - Whence a sphere of one foot in diameter, and of a like nature to the earth, would attract a small body placed near its surface with a force 20000000 times less than the earth would do if placed near its surface; but so small a force could produce no sensible effect. If two such spheres were distant but by...
الصفحة 59 - Society, contrived a method of determining the density of the earth, by rendering sensible the attraction of small quantities of matter; but, as he was engaged in other pursuits, he did not complete the apparatus till a short time before his death, and did not live to make any experiments with it.
الصفحة 13 - That there is a power of gravity pertaining to all bodies, proportional to the several quantities of matter which they contain.
الصفحة 11 - Jupiter from the sun by one ^^^ part of the whole distance — that is, by a fifth part of the distance of the utmost satellite from the centre of Jupiter ; an eccentricity of the orbit which would be very sensible. But the orbits of the satellites are concentric to Jupiter, and therefore the accelerative gravities of Jupiter, and of all its satellites towards the sun, are equal among themselves.
الصفحة 15 - It is true that we may regard one body as attracting, another as attracted; but this distinction is more mathematical than natural. The attraction is really common of either to other, and therefore of the same kind in both.
الصفحة 11 - If, at equal distances from the sun, any satellite, in proportion to the quantity of its matter, did gravitate towards the sun with a force greater than Jupiter in proportion to his, according to any given proportion, suppose of...
الصفحة 61 - I resolved to place the apparatus in a room which should remain constantly shut, and to observe the motion of the arm from without, by means of a telescope; and to suspend the leaden weights in such a manner, that I could move them without entering into the room. This difference in the manner of observing, rendered it necessary to make some alteration in Mr.
الصفحة 12 - The power of gravity is of a different nature from the power of magnetism ; for the magnetic attraction is not as the matter attracted. Some bodies are attracted • more by the magnet ; others less ; most bodies not at all. The power of magnetism in one and the same body may be increased and diminished ; and is sometimes far stronger, for the quantity of matter...
الصفحة 13 - I answer, that since the gravitation towards these bodies is to the gravitation towards the whole earth as these bodies are to the whole earth, the gravitation towards them must be far less than to fall under the observation of our senses. 1052 COR. 2. The force of gravity towards the several equal particles of any body is reciprocally as the square of the distance of places from the particles; as appears from Cor.