Aide-mémoire to the Military Sciences: Framed from Contributions of Officers of the Different Services, Volume 3

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J. Weale, 1862
 

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Page 455 - Again, if it be required to find the magnitude of the piston necessary for an engine of a given power, it is only necessary to multiply the number expressing the power by 28, and the square root of the product will be the diameter of the piston. 5. It must be carefully observed, however, that such rules are only applicable so long as the piston moves with the above velocity, and is urged by low-pressure steam at the above rate.
Page 367 - BART. [This paper, written in 1843, is valuable now, and is here reproduced from the fourth Edition of the present work.] THE importance of rolling roads, either newly constructed or when subjected to extensive repairs, seems never to have been duly appreciated. Lines of any length of new-laid broken stone may be deemed nearly impracticable to ordinary traffic ; the worst and most hilly old roads are always taken in preference to the new roads while in that state, although the latter may be much...
Page 501 - ... the pressure of the atmosphere, — and exerts an injurious counter-pressure against the piston, tending to increase the resistance to be overcome. To effect the free and rapid discharge, it is necessary not merely to open the communication to the exhausting pipe, but to open a wide passage, and to have this done by the time the piston recommences its motion. The valve alluded to cannot accomplish this. Its motion is gradual, not instantaneous.
Page 349 - This description of gravel is that which is by far the most frequently met with. The gravel selected for this purpose should be free from any kind of dirt, clay, or other impurity, and should consist of stones and sand, mixed in about such proportions that the latter would just fill the interstices of the former. The gravel should then be mixed with the proper quantity of ground unslaked lime — in ordinary...
Page 330 - ... by the horizontal length of the road, and divide the product by the inclined length of the same ; the quotient is the pressure required.
Page 328 - What additional increase in the length of a road would be equivalent to a given inclined plane upon it; or conversely, what inclination might be given to a road as an equivalent to a given decrease in its length? To satisfy this question...
Page 350 - All the irregularities of the upper part of the said pavement are to be broken off by the hammer, and all the interstices to be filled with stone chips firmly wedged or packed by hand with a light hammer, so that when the whole pavement is finished there shall be a convexity of four inches in the breadth of fifteen feet from the centre.
Page 286 - When the velocity of the hody is rendered greater than that due to the wave, the motion of the body is greatly facilitated. It remains poised on the summit of the wave in a position which may be one of stable equilibrium ; and this effect is such that, at a velocity of 9 miles per hour, the resistance is less than at a velocity of 6 miles per hour behind the wave.
Page 344 - ... the best roads; the surface of a road is much more efficiently drained by a small inclination in the direction of its length, than by a much greater transverse slope ; on this subject Mr. Walker has very justly...
Page 328 - ... passing between the places is not sufficient to warrant so great an outlay, it will become a matter of consideration whether the course of the road should be kept straight, its surface being made to undulate with the natural face of the country; or whether, a level or...

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