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Airy's altitudes apparatus Arthur's Seat Author Author Author Baille Baily Baily's balance ball Bertier bodies Bouguer calculated Cavendish Cavendish experiment centre centrifugal force Cetus corrections deflection determine diameter difference distance Divisions Time Point draw the arm earth effect equal error experiments Extreme points Divisions G. B. Airy globe gravitation constant Harton HENRY CAVENDISH hill Hutton inches Journ Jupiter la Condamine latitude length magnetic Maskelyne mean density ment Meridian Altitudes method middle point midway position moment of inertia mountain moved to negative moved to positive moving the weights negative position observations pendulum Peru Phil Phys Pichincha placed planets plumb-line point of rest positive position Poynting 185 proportion quantity of matter Quito radius ratio Reich Rozier Saigey Schehallien sea-level seconds-pendulum side specific gravity sphere spherical Sterneck surface suspended temperature tion toises torsion torsion balance ulum vertical vibration Weights moved wire
Page 3 - The boxes hanging by equal threads of eleven feet, made a couple of pendulums perfectly equal in weight and figure, and equally receiving the resistance of the air. And placing the one by the other, I observed them to play together forwards and backwards, for a long time, with equal vibrations.
Page 7 - 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.
Page 53 - 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.
Page 4 - 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...
Page 11 - Wherefore the absolute force of every globe is as the quantity of matter which the globe contains; but the motive force by which every globe is attracted towards another, and which, in terrestrial bodies, we commonly call their weight, is as the content under the quantities of matter in both globes applied to the square of the distance between their centres (by cor.
Page 4 - ... above. COR. 1 . Hence the weights of bodies do not depend upon their forms and textures; for if the weights could be altered with the forms, they would be greater or less, according to the variety of forms, in equal matter; altogether against experience, COR.
Page 92 - It, indeed, may be objected, that as the result appears to be influenced by the current of air, or some other cause, the laws of which we are not well acquainted with, this cause may perhaps act always, or commonly, in the same direction, and thereby make a considerable error in the result. But yet, as the experiments were tried in various weathers, and with considerable variety in the difference of temperature of the weights and air, and with the arm resting at different distances from the sides...
Page 5 - ... to every action corresponds an equal reaction ; therefore the planet B will, on the other hand, gravitate towards all the parts of the planet A ; and its gravity towards any one part will be to the gravity towards the whole as the matter of the part to the matter of the whole. QED Cor.
Page 6 - ... 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 showed that the earth is about four times more dense than Jupiter.