ما يقوله الناس - كتابة مراجعة
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الصفحة 347 - These clutches are simultaneously acted upon by the rods and small lever b, with the helical springs mm, and which, according as they are forced to the right or left, will enable the carriage to be moved forward or backward. To the fore naves are fixed two cylindrical metal rings, round which are two...
الصفحة 367 - ... that the actual distribution of heat in the earth's envelope is precisely that which would have taken place if the globe had been formed in a medium of a very high temperature, and had afterwards been constantly cooled. This accordance of the two kinds of observations is worthy of being remarked. The question of the terrestrial temperature has always appeared to us, adds M. Fourier, one of the greatest objects in cosmological studies ; and we have had it chiefly in view in establishing the mathematical...
الصفحة 347 - ... to be tightened by a lever convenient for the foot of the conductor, and which will readily retard or stop the coach when descending hills. K is the seat of the conductor, with the...
الصفحة 347 - ... of the road. To ascend steep parts of the road, and particularly when the carriage is used on railways, or to drag another behind it, greater friction will be required on the road than the two hind wheels will give, and there is therefore a contrivance to turn all the four wheels. This is done by...
الصفحة 158 - By the simple motion of a small handle, or index, placed oa a table, upon deck, in view and in hearing of the man at the helm, and of the master of the vessel, every movement which the engine is capable of giving to the paddle-wheel may be at once commanded. The vessel may be moved forwards or backwards, — or may be retarded, or entirely stopped, at any given moment, by merely turning the handle to the places denoted by the graduations of a dial-plate.
الصفحة 262 - At all events, Brydone has been grossly deceived in imagining that the seven beds of lava, seen lying one above another near the spot, have been sufficiently decomposed into vegetable mould. The substance which really intervenes between the beds, being nothing more than a sort of ferruginous tuff, just similar to what would be produced by a shower of volcanic ashes, such as usually precedes or follows an eruption of lava, mixed up with mud, or consolidated by rain.
الصفحة 100 - ... around. The beauty and novelty of such a scene in the animal kingdom, long arrested my attention, but after twenty-five minutes of constant observation, I was obliged to withdraw my eye from fatigue, without having seen the torrent for one instant change its direction, or diminish, in the slightest degree, the rapidity of its course.
الصفحة 100 - On moving the watch-glass, so as to bring one of the apertures on the side of the Sponge fully into view, I beheld, for the first time, the splendid spectacle of this living fountain vomiting forth from a circular cavity an impetuous torrent of liquid matter, and hurling along, in rapid succession, opaque masses, which it strewed everywhere around. The beauty and novelty of such a scene in the animal kingdom long arrested my attention ; but after twenty-five minutes of constant observation, I was...
الصفحة 243 - Whence it appears, that the mechanical power, or the power of a steam engine to impel a boat in still water, must be as the cube of its velocity. Therefore, if an engine of twelve horses...
الصفحة 88 - For some time past, his attention has been turned to the application of the steamengine to the purposes of navigation. He has now accomplished, and evidently shown to the world, the practicability of this, by executing it upon a small scale. A vessel, twenty-five feet long and seven broad, was, on the above date, driven with two wheels by a small engine.