At the head of these artificial rivers, stands the Grand Canal in the State of New York, connecting Lake Erie at Buffalo with the Hudson river at Albany. Its length is three hundred and sixty-three miles; with six hundred and eighty feet of lockage. It is consequently about four times as long as the longest canal in England. It is forty feet wide at top, twenty-eight at bottom, and four feet deep. Its aggregate rise and fall is six hundred and fiftyfour feet, effected by eighty-one locks. This great work was begun in 1817, and was finished in 1825; costing the State about five millions of dollars. Aм. ED.]

Under the present head, my main object is to notice the architectural skill, which this branch of improvement has called forth; and I shall therefore confine myself to the notice of aqueducts, which, in some situations, form the most difficult part of the art, as connected with the construction of canals. When the course of a canal crosses that of a river, it becomes necessary to build a bridge, and, upon it, in place of a common road, to form a channel and towing-path for the canal; the height of the aqueduct being regulated by the relative levels of the river and canal, and its breadth by that of the canal. Most works of this kind differ little from that of a roadbridge of similar dimensions. But, about the year 1795, Mr. Telford, having been intrusted with the management of the Shrewsbury and Ellesmere Canals, had his attention drawn to the construction of some large aqueducts; and having observed, in several instances, the masonry of aqueducts, where puddle was employed, to be cracked, and very subject to leakage, was led, by these circumstances, to employ cast-iron work in forming the bed of the canal. This he did, in the first instance, upon the Ellesmere Canal, at Crick, where the aqueduct was six hundred feet long, and sixty-five feet high above the river. Here he rejected the method of puddling; built the spandrels over the arches, with longitudinal walls only; and across these walls laid flaunched plates of

* [Puddle is a well-tempered mixture of clay, worked by the hands, for the purpose of excluding water. Spandrels are the spaces between the outside curve of an arch and the line which surmounts it.-AM. ED.]

cast-iron, as a bottom to the canal, and the means of binding the walls horizontally. These were well jointed, screwed, and caulked; while the sides of the waterchannel were built of stone facings, and brick hearting, or back, laid in water-lime mortar. By this mode, the quantity of masonry was much reduced, and the purpose, at the same time, effectually secured.

On the same canal, it was found necessary to cross the river Dee, at the bottom of the fine valley of Llangollen, at Pontcysylte, at the height of nearly a hundred and thirty feet above the surface of the river, and for a thousand feet in length. In this stupendous work, Mr. Telford introduced a still more decided deviation from the usual form, by building upright piers only, and, instead of arches of masonry, placing cast-iron ribs between them, constructing the canal part by cast-iron flaunched plates, for the sides as well as the bottom; and, in order to preserve as much as possible of water-way, projecting the towing path over the water in the canal. The canal part is twelve feet in width, which admits boats of seven feet beam, and a towing-path. Where the embankment commences, the height is seventy-five feet, and it is carried, on both sides, to an extent amounting in all to fifteen hundred feet.

This is probably the greatest aqueduct and embankment ever made for a navigable canal. Other works of the same kind, however, have since been constructed, of great magnificence, among which I may mention the three aqueducts erected on the Edinburgh and Glasgow Union Canal, in which the modes of the two aqueducts already mentioned have been combined; that is to say, the masonry of the arches and spandrels are finished as at Crick, and cast-iron plates for the bottom and sides, as in Pontcysylte, are introduced within the masonry. An improvement is made in the piers, by forming them hollow throughout; which mode, with an equal quantity of masonry, embraces a greater extent of base, and, having more external, as well as internal, surface, insures better materials and workmanship.

It is probable, that the art of canal-making has now

arrived at its climax, being about to be superseded by an improvement of vast importance,-that of locomotive engines on railways; but the necessity of large structures for crossing rivers and ravines will not, on this account, be dispensed with, and we are perhaps destined to see works, in the progress of this new mode of conveyance, which, in magnificence of design, and skill of execution, shall prove that the art is as yet but in its infancy. The wonderful and unexpected progress which but a few years have made in the power of transit, both as regards extent and speed, has left no bounds to the imagination in looking forward to the future.

ELEVENTH WEEK-SATURDAY.

RAILROADS WITH LOCOMOTIVE ENGINES. THE LIVERPOOL AND MANCHESTER RAILWAY.

THERE is another species of construction, of great magnitude and importance, noticed at the close of the last paper, to which the present advanced state of science and of commercial intercourse has given rise, and which, though not necessarily connected with architecture, sometimes, like the canal, of which it is the successful rival, draws largely on the resources of this art. Į allude to the railroad. This, in its simplest form, is not a recent invention. Nearly two centuries have elapsed since the introduction of tram-roads,* rudely constructed of wood, which were afterwards improved by the substitution of iron. In the last quarter of a century, this mode of conveyance has rapidly increased, especially in the neighborhood of Newcastle and Sunderland, where railroads have for some time been employed by private companies for the transportation of coals to the Tyne and Wear.

The first public railway for the conveyance of general merchandise and passengers, as well as of coals, was that

* [Tram-roads, or track-ways, are a rude kind of railroad.-AM. ED.]

of Stockton and Darlington, which was opened in September, 1825. In 1822, a similar undertaking was projected, for facilitating the intercourse between Liverpool and Manchester; but it was not till after numerous delays and discouragements that it was completed.

The sagacious projectors of this latter undertaking, were, on good grounds, sanguine of success. Liverpool, as a commercial seaport, is second only to London; while Manchester is an immense manufacturing town, and the centre and focus of a populous manufacturing district; and although an incessant interchange of commodities, amounting to upwards of a thousand tons per day, and constantly increasing, subsisted between these two towns, the modes of conveyance were tedious. These encouragements to the new undertaking, induced the projectors to persevere, and they at last effected their object, at an expense of not less than eight hundred thousand pounds.

On the 15th of September, 1830, this celebrated railroad was partially opened; and, on the 4th of December following, it was, for the first time, subjected, by way of experiment, to a full load of merchandise, in eighteen wagons, the gross weight of which, independent of the engine, was about eighty tons. This enormous load, which, if drawn along the turnpike road, would have required eighty horses, employed for the period of sixteen hours, was conveyed from Liverpool to Manchester in less than three hours, by a single locomotive engine. This, however, is considerably more than the ordinary burden, and less than the usual speed. The distance, which is upwards of thirty miles, is commonly passed in about an hour and a half, being at the rate of twenty miles in the hour. But, in descending inclined planes, the speed is not less than thirty or thirty-five miles an hour.

The utility and safety of this stupendous undertaking, were thus established, and its success was secured, although it was not till some time afterwards that it was in full operation. By the end of the year 1830, that is, in three months and a half, notwithstanding the imperfect state of the preparations, upwards of 70,000 passengers

had been conveyed along the line to various distances. Since that time, the amount of traffic, and of passengers, has far exceeded the expectations of the projectors, and has been rapidly progressive. In the year 1832, the gross receipts were £155,600; and in 1836, they amounted to £234,600.

The nature of a railway is too well known to require a particular description. In the work of which I now speak, there were both peculiar facilities and difficulties. The general face of the country was sufficiently level; but there were places which had to be excavated to the depth of sixty or seventy feet in the solid rock, and others which required extensive embankments; while, in one place, a valley was to be passed by a viaduct of nine arches, each fifty feet in span, and, in their greatest height, seventy feet. A peculiar difficulty occurred in carrying the line across an extensive morass or bog, in some places between thirty and forty feet deep, and so nearly approaching to a fluid state, that an iron rod would sink through it by its own gravity. But this obstruction was also overcome by skill and perseverance.

It is

There was yet another important operation connected with this undertaking, which was also successfully accomplished, that of gaining access to the river Mersey, by a tunnel excavated beneath the town. The length of this tunnel is two thousand two hundred and fifty yards. cut through various strata of red sandstone, blue shale, and clay, sometimes arched artificially, and at other times supported by the natural strength of the stone in which it is excavated. The height from the roof to the surface of the ground, varies from five to seventy feet.

I have given these details, because this spirited undertaking may be regarded as the commencement of a new era in the history of human intercourse.

A well-written pamphlet, published by the treasurer of the Liverpool and Manchester Company, in 1830, soon after the opening of the railway, to which I am indebted for most of the above information, contains the following just and interesting remarks. "Perhaps the most striking result produced by the completion of this railway, is,