Lectures on Select Subjects in Mechanics, Hydrostatics, Hydraulics, Pneumatics, Optics, Geography, Astronomy, and Dialling, Volume 1

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Stirling & Slade, and Bell & Bradfute, 1823 - Eclipses
 

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Page 41 - ... 2. When the prop is at one end of the lever, the power at the other, and the weight between them.
Page xii - I saw the spring-box with part of the chain round it, and asked him what it was that made the box turn round ; he told me that it was turned round by a steel spring within it. Having then never seen any other spring than that of my father's gun-lock, I asked how a spring within a box could turn the box so often round as to wind all the chain upon it. He answered that the spring was long and thin, that one end of it was...
Page 228 - Those which appear largest, are called stars of the first magnitude ; the next to them in lustre, stars of the second magnitude ; and so on to the sixth, which are the smallest that are visible to the bare eye.
Page 293 - ... 49", which wants 28' 11" of being as nearly in conjunction with the same node at the end of the period as it was at the beginning...
Page xiii - ... the time of the day when the sun shone out, by the boundary where the half of the globe at any time enlightened by the sun was parted from the other half in the shade ; the enlightened parts of the terrestrial globe answering to the like enlightened parts of the earth at all times. So that, whenever the sun shone on the globe, one might see to what places the sun was then rising, to what places it was setting, and all the places where it was then day or night throughout the earth.
Page 45 - THE WHEEL AND AXLE. 91. The proportion for the wheel and axle (in which the power is applied to the circumference of the wheel, and the weight is raised by a rope, which coils...
Page xxi - Having never had a grammatical education, nor time to study the rules of just composition, I acknowledge that I was afraid to put it to the press ; and for the same cause, I ought to have the same fears still.
Page 13 - The broader the base, and the nearer the line of direction is to the centre of it, the more firmly does a body stand, and the narrower the base of a body, and the nearer the line of direction is to the side of it, the more easily will it be overthrown.
Page 210 - York, to find what hour it is in any other part of the world.—Bring the given place, to the meridian, and set the index to the given hour; then turn the globe till the other place come to the meridian, and the hour at which the index points will be the time sought.
Page 311 - For, the upward pressure against every part of the board (which the bladder touches) equal in area to the area of the bore of the tube, will be pressed upward with a force equal to the weight of the water in the tube ; and the sum of all these pressures, against so many areas of the board, will be sufficient to raise it with all the weights upon it. In my opinion, nothing can exceed this simple machine, in making the upward pressure of fluids evident to sight.1*0 Nate ISO.

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