Game of chess 110 15 Method of making transparent soap 368 485 328 250 128 455 486 487 13 367 56 My grandfather's legacy 108, 152, 206, 328 231, 266, 314, 350, 388, 460 93 99 486 448 87 New method of bleaching sponge 287 56 457 311 11 269 403 407 442 167 Of the ploughman that sayde bis pa- 448 ternoster 88 488 390 76 Patent for British cashmere 326 Peep at the pilgrims 143 48 Poems on sacred subjects, notice of 441 Poetic hours, notice of 442 Popular Fallacies 449 319 487 454 408 388 Progress of playhouses 405 * Puritans," the term 328 Pythagorean objections to animal 372 448 247 125 368 Queen Elizabeth's manuscript, disco- 487 127 287 Race, the word 199 485 88 341 239 196, Retrospect of the efforts and progress of mankind during the last twenty 375 361 79, Very of say by five years 9, 49 443 oceans Rings 288 243 328 51 The two brothers, a Hungarian tale 429 228 248 To make flat iron bars steel only half 128 through 190 To restore the color of woollen cloths 327 352 Tom Cordery: a character 88 Troubadour, the 47 Unguarded moment, the 228 488 Union of the Atlantic and Pacific 347 208 Unpublished essay by mad. de Stael 324 407 108 409 Utility of letters of recommendation 424 324, 367, 405, 446, 485 17 Victor Leoni, or the Venetian captive 302, 336 88 400 407 Voltaire, anecdote of 287 301 War, brutalizing tendency of, &c 38 322 447 248 Weaving in India 441 126 50 129, 175 156, 171 448 79, POETRY. Ballad romance 268 Oh! sweet comes the zephyr's breath 75 309 74 459 216 289 140 182 387 60 167 289 by a mother to her infant 346 196 436 29 Specimens of ancient poetry 344 268 309 to Jessy 37 to 189 442 61 The lot of thousands 436 114 460 To Alice To know each fishes haunt 345 167 Trust not, oh, trust not Venetian song 219 38 237 92 TH THE strong feeling of interest and come into general use, that the ex curiosity which this subject is pense of transporting commodities now exciting in the public mind; the will be about two-thirds less than on variety of companies which are dai- the best roads. ly forming, to connect, by means of With respect to the advantages of rail-ways, the most important mer a rail-way over a canal, which is the cantile and manufacturing stations in question here principally at issue, we the kingdom; the secret opposition may observe, in the first place, that which is now vigorously exerting if a horse power effect three times as itself on the part of interested bodies, much on a canal as on a rail-way, with any object in view but the pub- the original cost and subsequent relic good; seem to point out the pro- pairs of a canal are about three times priety of setting before the public a as great ; consequently, a canal will general view of the advantages which require about the same rates or dues rail-ways are likely to furnish, and to to repay the proprietors as a raildirect their attention to the quarters way. It must next be observed, that whence opposition may be expected. this comparison relates entirely to On a well made road a horse will the transporting of goods at two miles draw one ton, in a cart weighing an hour. Now it is easy to show, about 7cwt., or about 3000lb., at a that so long as horse power is emrate of two miles an hour. ployed on canals, and they are not rail-way of the best construction he suficiently deep and broad to admit will draw, at the same rate of trave the application of steam, this rate of elling, about 15 tons ; let us call this transporting goods cannot be increas30,000lb. for the convenience of hav, ed without an increase of freight, ing round numbers; and on a canal which would entirely destroy their he will draw about 30 tons in a boat superiority over roads. We have weighing 15 tons, or about 90,000lb. seen that a horse will draw about Hence, on a rail-way, the draught of 90,000lb. at the rate of two miles an a horse is ten times, and on a canal hour. If we increase the velocity of tkirty times, as great as on a well the boat, the resistance will also be made road. Now a rail-way costs increased, and with amazing rapidity. about three times, and a canal about The resistance of a fluid increases as nine times, as much as a good road ; the square of the velocity. Since and it is probable that the expense 90,000lb., therefore, is drawn at the of keeping them in repair, is in pro- rate of two miles an hour by one portion to the original outlay. It is horse ; obvious, therefore, if railways should 1 ATHENEUM, VOL. 3. 2d series, On a 12 6 8 At 4 miles an hour it would require 4 increasing the velocity on a rail-way, 6 9 the resistance is not at all increased; 8 16 it is, if any thing, rather diminished. 36,3 Abstracting from consideration the Or, At 4 miles an hour, the draught of 1 horse resistance of the air, the very force will be about 22,0001b. which impels a body at two miles an 10,000 hour, may, by very simple contriv5000 ances, be made to impel it at ten or 12 2000 twelve miles an hour. If we apply to In this computation it is assumed the body to be moved on a rail-way, that the draught of a horse is the a force just equal to the resistance same at two, four, six, and eight miles due to the friction, it will not move; an hour. In fact, however, its draught it will be exactly in a state of equidiminishes very rapidly as its veloci- librium. But the smallest increase ty increases, a great portion of its of force will put it in motion. If this strength being exhausted in support- small increase of force be a constanting its velocity. If inolb. measurely acting force, like that due to the force of traction of a horse, when steam, its motion will be continually travelling at the rate of two miles an accelerated, and would, ultimately, hour, then will this power be reduced become greater than any assignable to 641b, when he travels at the rate limit. llere we see the advantage of four iniles an hour; and for high- of steam power; animal power could er rates of travelling it diminishes never be so applied as to produce still more rapidly. Here the draught this effect; because, as the velocity of a horse on a canal, at the rate of of the vehicle increases, the draught four miles an hour, is little more than of animal power is diminished, be12,000lb. It is needless to push this coming small indeed when it reachinquiry any farther ; it is quite cleares the velocity of ten or twelve that goods can never be transported miles an hour. When the vehicle on a canal at a rate exceeding two has attained any proposed velocity, or two and a half miles an hour.- whether that velocity be generated Let us sce now what will be the ef- in the first instance by the continued fect of an increased rate of travelling action of the impelling force, or by on a rail way. And here we shall any other means, it is merely necesarrive at a series of conclusions dia- sary, in order that it should retain metrically opposite to those we liave that velocity, that there should be an deduced for canals. The resistance impelling force just suficient to overto communication of motion on come the friction and the resistance rail-way arises from the friciion and to the air. Hence, on a rail-way, the resistance of the air. For any the erpenditure of force due to a verate of travelling which is likely to locity of ten or twelve miles an hour, be adopted, 8, 10, or 12 miles an is very little more than that due to a hour, the resistance arising from the velocity of two miles en hour. This atmosphere is very triting compared is the grand mechanical advantage with that due to the friction. We which a rail-road possesses over a shall, therefore, altogether neglect its canal. But it is on the application consideration. The resistance due to of steam, and on a consequent capathe friction is proportional only to city of m:intaining a constant action, the pressure. It is entirely indepen, however great the velocity of the vedent of the velocity. This is the hicle, that this advantage depends. grand circumstance which distinguish. Without steam a railway would be of es a rail-way from a canal, and which no use ; it would possess no superigives the former such an immense ority over a canal. Animal power advantage over the latter. On a ca- could not have been applied with nal, by incrcasing the velocity of the any advantageous effect, because its boat, we increase the resistance to draught diminishies so rapidly with its motion at a very rapid rate ; by an increase of velocity. a |
0 Reviews Reviews aren't verified, but Google checks for and removes fake content when it's identified Write review |