brick, are given by the engineers, who, at the same time, determine the centres, if necessary, from these data. The builder lays a small layer of concrete, at least three inches, whose top shall be as high as the top of the peg just set. On the concrete he proceeds to build the side walls of the aqueduct. You may see the dimensions by the plan better than I could tell you. The side walls being done, they are filled in behind them, up to the top, with earth, to prevent strain or damage, also to act as a support, and cover up the work as fast as possible. Then the concrete is laid for the bottom of the reversed arch in brick, by means of moulds placed every ten feet apart. When thoroughly set, the brick work is commenced. Selecting the best brick (and it has all been most thoroughly inspected,) the reversed arch is laid, and then the "brick-facing" that is, facing the inside of the wall with brick, when carried up to the top of the wall. The upper arch, consisting of two ring courses (with occasional headers,) is thrown; the arch is covered with a thick coating of plaster, and the angle made by the top of the wall and arch filled with the same kind of masonry as the side walls; and then the aqueduct is done. You will perceive it to be a long brick vault stretching from New York to Croton, ascending at the rate of thirteen inches in a mile. The earth removed in the excavation is then "back filled" over the aqueduct until it is four feet deep over the crown of the arch, level on top, and ten or eight feet wide, and the sides slope one and a half to one, (as you see in the figure.) When the ground is too steep, a "protection wall" is introduced, (see drawing;) this is laid dry, i. e., without mortar, and made to slope one half to one, as in the drawing, or one to one, at an angle of fortyfive degrees. So much for the aqueduct "in open cutting in earth." When a valley is crossed, a heavy wall fifteen feet wide on top, with sides sloping one-twelfth to one, must be built. They are large stones firmly imbedded in small broken ones. On the top of this wall, a foot of concrete is placed; the aqueduct, as usual, is built on that. As water passes through valleys, a stone passage way, called "a culvert," is made of suitable dimensions. Cugnot's Steam Carriage. The improvements of the mechanism of the steam engine, stimulated many projects for adapting its agency to other pur poses besides that of raising water; and the scheme of John Theophilus Cugnot, a native of Void, in Lorraine, is meritorious for its novelty and its successful practical development. In his youth, Cugnot served in Germany as an engineer. Passing after wards into the service of Prince Charles of Lorraine, he resided at Brussels, and gave lessons in the military art, with the theory and practice of which he was profoundly acquainted. The invention of a light gun procured him the notice of the Compte de Saxe, to whom, about 1763, he exhibited a model of a carriage moved by a steam engine, instead of horses. He afterwards lived at Paris, and through the recommendation of the Compte, obtained, in 1769, the patronage of the Duc de Choiseul, then minister at war. He was now enabled, at the public expense, to construct a large carriage moved by a steam engine, similar to that of the model he had shown years previously. At the first trials in 1770 of this novel vehicle, before a numerous assemblage of officers and professional persons, its movements were so violent as to overturn a portion of a wall that was opposed to its progress. This, unfortunately, produced an opinion, that in consequence of the uncertainty of obtaining proper mechanical control, its motion would be of small use in practice. The project was therefore abandoned, and the experimental machine was deposited in the museum of the Arsenal, to become a point of reference to the epigrammatist, and a memorial of the blasted hopes of the accomplished author. Cugnot's genius expanded half a century too soon, either for its value being known, or its efforts cherished. The re At a later period of life, his means of subsistence having fallen into decay, the various services he had rendered to the public were thought to entitle him to a reward from the state. volution sweeping away even this pitiful pension of twenty-one pounds a year, Cugnot must have perished with hunger, but for the compassionate benevolence of a lady of Brussels. With the kindness of her sex, she not only provided for the wants, but watched with tenderness over the personal comforts of the now feeble and helpless old man, until the well known Mercier succeeded in drawing the attention of Napoleon to the miserable fate of his aged and ancient friend. Cugnot died at Paris in 1805, in his 80th year, in a state to him of comparative affluence, from the enjoyment of a valuable annuity from Napoleon. Eloquent Description But about seventy years since, every thread used in the manufacture of cotton, wool, worsted, and flax, throughout the world, was spun singly by the fingers of the spinner, with the aid of that classical instrument, the domestic spinning wheel. In 1767, an eight-handed spinster sprung from the genius of Hargreaves; and the jenny, with still increasing powers, made its way into com. mon use in spite of all opposition. Two years afterwards the more wonderful invention of Wyatt, which claims a much earlier origin, but which had disappeared, like a river that sinks into a subterraneous channel, now rose again under the fortunate star of Arkwright, claiming yet higher admiration, as founded on principles of more extensive application. Five years later the happy thought of combining the principles of these two inventions, to produce a third, much more efficient than either, struck the mind of Crompton, who, by a perfectly original contrivance, effected the union. From twenty spindles this machine was brought, by more finished mechanism, to admit of a hundred spindles, and thus to exercise a Briarean power. Kelly relinquished the toilsome method of turning the machine by hand, and yoked to it the strength of a rapid river. Watt, with the subtler and more potent agency of steam, moved an iron arm that never slackens or tires, which whirls round two thousand spindles in a single machine. Finally, to consummate the wonder, Roberts dismisses the spinner, and leaves the machine to its own infallible guidance. So that at the present time several thousand spindles may be seen in a single room, revolving with inconceivable rapidity, with no hand to urge their progress, or to guide their operations-drawing out, twisting, and winding up as many thousand threads with unfailing precision, indefatigable patience and strength,-a scene as magical to the eye that is not familiar to it, as the effects have been marvellous in augmenting wealth and population. If the thought should cross any mind, that, after all, the genius of man has been expended in the insignificant object of enabling men better to pick out, arrange, and twist together the fibres of a vegetable wool,—that it is for the performance of this minute operation that so many energies have been exhausted,so much capital employed,-such stupendous structures reared, and so vast a population trained up-we reply: An object is not insignificant because the operation by which it is effected is minute: the first want of men in this life, after food, is clothing, and as this art enables them to supply it far more easily and cheaply than the old methods of manufacturing, and to bring cloths of great elegance and durability within the use of the humble classes, it is an art whose utility is only inferior to that of agriculture. It is almost impossible to over-estimate the importance of these inventions. The Greeks would have elevated their authors among the gods; nor will the enlightened judgment of modern times deny them the place among their fellow men, which is so undeniably their due. 482 ANECDOTES, DESCRIPTIONS, ETC. A Watchmaker's Epitaph. The following professional epitaph is copied from a tombstone in Lidford Churchyard, Devon, England. Here lies in horizontal position George Routleigh, Watch Maker, Integrity was the "Main-spring, Humane, generous, and liberal, Till he had relieved distress. So sincerely "regulated" were all his move By People Who did not know Even then he was easily He had the Art of disposing his "Time" That his "hours" glided away In hopes of being "taken in Hand" Thoroughly "cleaned,"-" repaired," and "set In the World to come. |