Lectures on Experimental Philosophy, Astronomy, and Chemistry: Intended Chiefly for the Use of Students and Young Persons, Volume 1

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R. Phillips, 1808 - Astronomy
 

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Page 301 - ... 3°, it may be computed by proportional logarithms in the same manner as by common logarithms. If one of the terms be 3h or 3°, its proportional logarithm need not be considered in the operation, since it is equal to 0. Hence appears the use of proportional logarithms in finding Greenwich time from the distance of the moon from the sun or a fixed star. The variation of the distance in...
Page 58 - ... tons avoirdupois, a pressure which would be insupportable, and even fatal, were it not equal on every part, and counterbalanced by the spring of the air within us.
Page 171 - ABC sends out rays in all directions, some rays, from every point on the side next the eye, will fall upon the cornea between E and F; and by passing on through the humours and pupil of the eye, they will be converged to as many points on the retina or bottom of the eye, and will thereon form a distinct inverted picture cba of the object.
Page 301 - Ihould be taken from Two Stars, or the Sun and a Star on each Side of her, as often as Opportunity permits...
Page 80 - It comes on indiscriminately at any hour of the day, at any time of the tide, or at any period of the moon ; and continues sometimes only a day or two, sometimes five or six days, and has been occasionally known to last fifteen or sixteen days.
Page 177 - I thought the regular effects of the first prism would be destroyed by the second prism, but the irregular ones more augmented by the multiplicity of refractions. The event was that the light, which by the first prism was diffused into an oblong form, was by the second reduced into an orbicular one, with as much regularity as when it did not at all pass through them.
Page 126 - ... square feet, which reflecting only about half what falls upon it, the quantity of matter contained in the rays of the sun incident upon a square foot and a half of surface in one second of time, ought to be no more than the twelve hundred millionth part of a grain.
Page 219 - D will be moved one tooth by the screw; and, therefore, in forty-eight revolutions of the winch, the wheel D will be turned once round. Then, if the circumference of a circle, described by the handle of the winch A, be equal to the circumference of a groove...
Page 213 - A ed 3 times as far from the prop as the power P acts at F, by the cord C going over the fixed pulley D ; in this case, the power must be equal to three pounds, in order to support the weight.
Page 171 - But that vision is effected in this manner may be demonstrated experimentally. Take a bullock's eye while it is fresh, and having cut off the three coats from the back part, quite to the vitreous humour, put a piece of white paper over that part and hold the eye towards any bright object, and you will see an inverted picture of the object upon the paper. Since the image is inverted, many have wondered why the object appears upright. But we are to consider, 1. That inverted is only a relative term;...

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