Lectures on Select Subjects in Mechanics, Hydrostatics, Hydraulics, Pneumatics, Optics, Geography, Astronomy, and Dialling, Volume 2

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Stirling & Slade, and Bell & Bradfute, 1823 - Astronomy - 400 pages
 

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Page 114 - A Description and Draught of a new-invented Machine, for carrying Vessels or Ships out of, or into, any Harbour, Port, or River, against Wind and Tide, or in a calm.
Page 282 - ... our situation unavoidably inspired. This appeared to me the more remarkable, as my case was totally the reverse. I was in a state of excitement resembling the effect of some spirituous liquor. I suffered no pain ; I experienced only a strong pressure round my head, as if an iron circle had been bound about it. I spoke with the workmen, and had some difficulty in hearing them. This difficulty of hearing rose to such a height, that during three or four minutes I could not hear them speak. I could...
Page 107 - ... alternately admitting the steam to the different sides of the smaller piston, while the steam last admitted into the smaller cylinder passes alternately to the different sides of the larger piston in the larger cylinder, the top and bottom of which are made to communicate alternately with the condenser. In an engine working with the improvements which have been...
Page 282 - To remedy that inconvenience, the workmen instructed us, after havingclosed our nostrils and mouth, to endeavour to swallow, and to restrain our respiration for some moments, in order that, by this exertion, the internal air might act on the Eustachian tube. My companion, however, having tried it, found himself very little relieved by this remedy. After some minutes, we resumed our descent. My friend suffered considerably; he was pale; his lips were totally...
Page 90 - I have seen the water run like a constant fountain stream forty feet high ; one vessel of water rarefied by fire driveth up forty of cold water. And a man that tends the work is but to turn two cocks, that one vessel of water being consumed, another begins to force and re-fill with cold water, and so successively, the fire being tended and kept constant, which the self-same person may likewise abundantly perform in the interim between the necessity of turning the said cocks.
Page 34 - ... of the wheel. 7. Then, as the number of revolutions of the wheel in a minute is to the number of revolutions of the millstone in a minute, so must the number of staves in the trundle be to the number of teeth in the wheel in the nearest whole numbers that can be found.* 8.
Page 106 - ... pounds the square inch entering above the smaller piston, will carry it downwards, while the steam below it, instead of being allowed to escape into the atmosphere or applied to any other purpose, will pass into the larger cylinder above its piston, which will take its downward stroke at the same time that the piston of the smaller cylinder is doing the same thing ; and while this goes on, the steam which last filled the larger cylinder, in the upward stroke of the engine, will be passing into...
Page 99 - ... shall shew some degree of exhaustion, after which, the repetition of blowing will soon empty the cylinder of air. The piston being then at the top of its stroke, the valves G and L are to be opened, and the fly-wheel m turned by hand about one-eighth of a revolution, or more, in the direction in which it is intended to move ; the steam which is then in the cylinder will pass by L into the condenser, when, meeting the jet of water from the injection-cock, it will be converted into water, and the...
Page 61 - B, are two apertures in opposite directions. When water from the millcourse MN is introduced into the tube TT, it flows out of the apertures A, B, and, by the reaction or counterpressure of the issuing water, the arm AB, and consequently the whole machine, is put in motion. The bridgetree ab is elevated or depressed by turning the nut c at the end of the lever c b.
Page 52 - ... from this rule, before they will lose their power, by a given aliquot part of the whole, than low ones can be admitted to do ; for a wheel of 24 feet high may move at the rate of six feet per second without losing any considerable part of its power ;* and, on the other hand, I have seen a wheel of 33 feet high, that has moved very steadily and well with a velocity but little exceeding 2 feet.-fIV.

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