The Useful Arts: Considered in Connexion with the Applications of Science: with Numerous Engravings, 第 2 卷Marsh, Capen, Lyon, and Webb, 1840 |
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acid Alleghany Mountains alloy angle applied arbor atmosphere axis axle boat boiler bottom called canal carbon carbonic acid carriages cavity centre circumference clay color common condenser consists constructed copper cotton cupellation cylinder degrees direction ductile effect elastic force employed engine equal Erie canal feet fibres fluid friction furnace fusee glass gold gunpowder hammer heat hole Hollidaysburg hundred inches inclined planes iodine iron kind length lever locomotive machine machinery Mechanical Philosophy metal miles mode Morris canal motion mould moving nitric acid oblique operation oxide pass pieces pinion pipe piston placed plate portion pressure produced pumice pump quantity rack rail-road rail-way rails raised ratchet-wheel revolving River rollers round sails side silver sometimes specific gravity steam steam-engine steel stone strata substance sufficient surface teeth temperature threads tion tooth tube turn valve veins velocity vessel vitrified weight wheel wind
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第 34 頁 - Locks are tight, oblong enclosures, in the bed of the canal, furnished with gates at each end, which separate the higher from the lower parts of the canal. When a boat passes up the canal, the lower gates are opened, and the boat glides into the look, after which the lower gates are shut.
第 303 頁 - ... one is struck with the temporary and apparently unfinished state of many of the American works, and is very apt, before inquiring into the subject, to impute to want of ability what turns out, on investigation, to be a judicious and ingenious arrangement to suit the circumstances of a new country, of which the climate is severe, — a country where stone is scarce and wood is plentiful, and where manual labor is very expensive.
第 249 頁 - Lime is often employed, in small quantities ; also borax, a salt which facilitates the fusion of the silica. Instead of the common alkalies, the sulphate of soda may be employed, in glass-making. But, in this case, it is necessary to liberate the alkali, by decomposing the sulphuric acid of the salt. This may be done, by charcoal, or, in flint-glass, by metallic lead. Lime is also used with this salt. Of the metallic oxides, which are added in different cases, the deutoxide of lead (red lead) is...
第 125 頁 - Cornwall, performs as much labour as a day's work of fifty such horses. The great pyramid of Egypt stands upon a base measuring seven hundred feet each way, and is five hundred feet high, its weight being twelve thousand seven hundred and sixty millions of pounds. Herodotus states, that in constructing it one hundred thousand men were constantly employed for twenty years. The materials of this pyramid would be raised from the ground to their present position by the combustion of about four hundred...
第 278 頁 - Sometimes, however, rocks intercept the way, which require great labor to penetrate ; but this is always effected by pecking, which slowly pulverizes the stone. The most unpleasant circumstance attendant upon this business, is the occasional breaking of a rod into the hole, which sometimes creates a delay of many days, and an incalculable labor in drawing up the lower portion.
第 97 頁 - B which are shut up, will be pressed outwards by a force equal to the weight of a column of water whose height is TT, and whose area is the area of the apertures. Every part of the tube AB sustains a similar pressure; but as these pressures are balanced by equal and opposite pressures, the arm AB is at rest. By opening the aperture at A, however, the pressure at that place is removed, and consequently...
第 184 頁 - ... weakening the fibres. The pulp, composed of the fibrous particles mixed with water, is transferred to a large vat, and is ready to be made into paper. The workman is provided with a mould, which is a square frame with a fine wire bottom, resembling a sieve, of the size of the intended sheet. With this mould he dips up a portion of the thin pulp, and holds it in a horizontal direction. The water runs out through the interstices of the wires, and leaves a coating of fibrous particles, in the form...
第 258 頁 - Thr oxide of tin renders this of a beautiful white, the perfection of which is greater when a small quantity of manganese is likewise added. If the oxide of tin be not sufficient to destroy the transparency of the mixture, it produces a semi-opaque glass, resembling the opal.
第 365 頁 - The portion covered by the object retains the original bright yellow tint which it had before exposure, and the object is thus represented yellow upon an orange ground, there being several gradations of shade, or tint, according to the greater or less degree of transparency in the different parts of the object. " In this state, of course, the drawing, though very beautiful, is evanescent. To fix it, all that is required is careful immersion in water, when it will be found that those portions of the...
第 303 頁 - Undressed slopes of cuttings and embankments, roughly built rubble arches, stone parapet-walls coped with timber, and canal-locks wholly constructed of that material, every where offend the eye accustomed to view European workmanship. But it must not be supposed that this arises from want of knowledge of the principles of engineering, or of skill to do them justice in the execution. The use of wood, for example, which may be considered by many as wholly inapplicable to the construction of canal-locks,...