The Mechanics' Magazine, Tập 60

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Robertson, Brooman, and Company, 1854
 

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Trang 204 - His mischief shall return upon his own head, and his violent dealing shall come down upon his own pate.
Trang 177 - an obvious oversight," Professor Forbes contends in an ingenious and apparently unanswerable manner. The vibrations, he urges, depend upon the difference of temperature existing between the rocker and the block ; if the latter be a bad conductor and retain the heat at its surface, the tendency is to bring both the surfaces in contact to the same temperature, and thus to stop the vibration instead of exalting it. Further, the greater the quantity of heat transmitted from the rocker to the block during...
Trang 107 - STEAM ENGINE.— The Steam Engine, for Practical Men, containing a theoretical investigation of the various rules given in the work, and several useful Tables, by James, Hann, AICE, and Placido and Justo Gener, Civil Engineers, 8vo, cloth, 9s. "To the practical and scientific Engineer, and to the Assistant Engineer, who aspires to pass his examination for chief with credit to himself, and the Service...
Trang 175 - ... hot silver, and that when the vibrations ceased the sound ceased also. Professor Gilbert merely stated the facts, and made no attempt to explain them. In the year 1829, Mr. Arthur Trevelyan, being engaged in spreading pitch with a hot plastering iron, and once observing that the iron was too hot for his purpose, he laid it slantingly against a block of lead which chanced to be at hand; a shrill note, which he compared to that of the chanter of the small Northumberland pipes, proceeded from the...
Trang 243 - ... on the same body. The essential parts are merely a bar capable of rotating freely about one end of an axis, (and loaded at its extremities to keep up the rotation,) while the axis itself can turn about a point in its length near* the end carrying the bar, upon a horizontal axis, capable of moving freely round a vertical pillar. At the lower end of the first axis is a weight which more than counterpoises the upper part. If then there be no rotation in the bar about the first axis, the effect of...
Trang 177 - ... an expansion of the general mass. Imagine the conductive power of the block to be infinite, that is to say, that the heat imparted by the rocker is instantly diffused equally throughout the block ; then, though the general expansion might be very great, the local expansion at the point of contact would be wanting, and no vibrations would be possible. The inevitable consequence of good conduction is, to cause a sudden abstraction of the heat from the point of contact of the rocker with the substance...
Trang 356 - Subornation of perjury is the offence of procuring another to take such a false oath, as constitutes perjury in the principal.
Trang 245 - From these singular applications of a very simple mechanical truth, we may now turn to what is but another exemplification of the same thing, however apparently remote from those we have considered, and upon a far grander scale. The phenomenon of the Precession of Equinoxes was known to Hipparchus; but no explanation of the fact was for ages imagined. Even Kepler, in the multiplicity of his hypothetical resources, could not succeed in devising anything plausible. The axis of the Earth is slowly shifting...
Trang 245 - ... stated ; as is easily seen on the principle, and by means of the apparatus, before described. Thus it would follow that this extraordinary instance of savage invention, which long ago puzzled inquirers, is simply a case (like the last) of " the composition of rotatory motion." It should, however, be mentioned that some experimentalists have entertained a different view of the cause of deviation in this instance. Besides the results above stated, Professor Magnus (in the same Memoir) mentions...
Trang 461 - ... of the ash-pans of locomotives were subjected, had produced very serious results, which it sufficed to point out forcibly to guard against the recurrence of. The author contended, that presuming adequate dimensions to have been given to girders, and the stipulated weight not to have been exceeded, the chances of accident were remote, but that any repeated...

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