The next step in the increase of means of traffic was the construction of canals. The rivers had previously been rendered more navigable by removing obstructions, deepening channels, and making good towing-paths along their banks; but now it was projected to make artificial rivers. In this scheme, Richard Brindley, under the patronage of the Duke of Bridgewater, was the great engineer; and his intrepid genius dictated to him to carry these canals over hills by locks, over rivers by aqueducts, and through the heart of hills by tunnels. These enterprises at that moment appeared, to the ordinary run of civil engineers, as rash experiments, which were sure to prove abortive. As all new ideas are, these ideas, now so commonplace, were ridiculed by the wise ones as little short of madness. Mr. Brindley's first great work was the formation of the Duke of Bridgewater's canal, from Worsley to Manchester. In this he at once proved all his plans of locks, tunnels, and aqueducts. He conducted his canal by an aqueduct over the river Irwell, at an elevation of thirty-nine feet; and those learned engineers who had laughed at the scheme as "a castle in the air," might now see boats passing over the river at that height with the greatest ease, while other boats were being drawn up the Irwell against the stream and under the aqueduct with five times the labour. At Worsley the canal was conducted into the very heart of the coal-mine by a tunnel, with branches, which conducted the boats up to the different parts of the mine, so that the coal could be loaded on the spot where it was dug. The immediate effect of this canal was to reduce coals in Manchester to half the former price; and the canal being extended so as to connect it with the Mersey, at Runcorn, it reduced the freight of goods from Manchester to Liverpool to the same extent, from twelve shillings to six shillings per ton, the land carriage having been forty shillings. Brindley was next engaged to execute the Grand Trunk Canal, which united the Trent and Mersey, carrying it through Birmingham, Chesterfield, and to Nottingham. This was commenced in 1766, and exhibited further examples of his undaunted skill, and, as he had been laughed at by the pedants of the profession, he now in his turn laughed at their puny mediocrity. One of his tunnels, at Harecastle Hill, in Staffordshire, was two thousand eight hundred and eighty yards long, twelve feet wide, nine high, and in some parts seventy yards below the surface of the ground. This tunnel, after half a century's use, was found too confined for the traffic, and a new one, much wider, was made by Telford. By this time the art of tunnelling had made great progress, and whilst Brindley required eleven years to complete his tunnel, Telford made his much larger one in three. Many causes intervened to check for a time the progress of canals, so that from 1760 to 1774 only nineteen Acts were passed for them; but in the two years of 1793 and 1794 no fewer than thirty-six new Bills were introduced to Parliament, with others for extending and amending rivers, making altogether forty-seven Acts, the expenditure on the canals of these two years' projection amounting to five million three hundred thousand pounds. The work now went on rapidly, and investments in canal shares exhibited at that day, in miniature, the great fever of railway speculation at a later period. Lines of canals were made to connect the Thames, the Tweed, the Severn, and the Mersey; so that the great ports of London, Liverpool, Hull, and Bristol were connected by them, and put into communication with nearly all the great inland manufacturing towns. In 1779 a ship-canal was completed from the Forth to the Clyde—a work proposed as early as the reign of Charles II. This canal, thirty-five miles in length, had thirty-nine locks, which carried the canal to a height of one hundred and fifty-six feet above the sea, and it crossed the river Kelvin by an aqueduct eighty-three feet from the bed of the river to the top of the masonry. A few years later a much larger ship-canal united Gloucester to the Severn, and wonderfully increased the trade and growth of that city.

Telford succeeded to Brindley, with all his boldness and skill, and with much extended experience. He executed the Ellesmere canal, which occupied a length of upwards of a hundred miles, connecting the rivers Severn, Dee, and Mersey. In the construction of this canal Telford introduced a bold, but successful, novelty. In aqueducts, instead of puddling their bottoms with clay, which was not proof against the effects of frost, he cased them with iron, and adopted the same means when he had to pass through quicksands or mere bog. Some of Telford's aqueducts were stupendous works. The Chirk aqueduct passed, at seventy feet above the river, on ten arches of forty feet span, and cost twenty thousand eight hundred and ninety-eight pounds. The aqueduct over the Dee passed at a height of one hundred and twenty-one feet above low water, and consisted of a great trough of cast-iron plates, supported on eighteen piers, and having a towing-path of cast-iron, supported on cast-iron pillars. This aqueduct took ten years in building, and cost, with its embankments, forty-seven thousand pounds. Tunnels much larger than that at Harecastle Hill were executed. That at Sapperton, on the Thames and Severn canal, executed by Mr. Whitworth, was nearly two miles and a half long, ran two hundred and fifty feet below the summit of the hill, and was large enough for boats of seventy tons burden. This was completed in 1788. These daring enterprises led to the design of a tunnel under the Thames, from Gravesend to Tilbury; but this was abandoned for want of capital. In 1804 a like attempt was made at Rotherhithe, but stopped from the same cause, and was not completed till 1843 by Sir Mark Isambard Brunel. Between 1758 and 1801 no fewer than sixty-five Acts of Parliament were passed for making or extending canals. At the end of that period canals extended over upwards of three thousand miles, and had cost upwards of thirteen millions sterling. In fact, the bulk of canal work was done by this time, though not some few works of great importance. The Leeds and Liverpool canal, begun in 1770, but not completed till 1816, opened up connection with a vast manufacturing district; and the Rochdale, Huddersfield, and Hull canals gave access for the Baltic traffic into the heart of Lancashire. The Paddington and Regent's Canals wonderfully promoted the intercourse between the interior and the metropolis. In the Highlands, the Caledonian Canal, connecting the string of lakes between Inverness and the Atlantic, gave passage to ships of large burden. At the end of this reign the aggregate length of canals in England and Wales was two thousand one hundred and sixty miles; in Scotland, two hundred and twelve; in Ireland, two hundred and fifty; total, two thousand six hundred and twenty-two miles. The attention paid to roads and canals necessitated the same to bridges; and during this reign many new structures of this kind were erected, and much improvement attained in their formation. In 1776 a totally new kind of bridge was commenced at Coalbrook Dale, and completed in 1779; this was of cast-iron, having a single arch of one hundred feet span, and containing three hundred and seventy-eight and a half tons of metal. Telford greatly improved on this idea, by erecting an iron bridge over the Severn, at Buildwas, in 1796, having an arch of one hundred and thirty feet span.

WATERLOO BRIDGE, LONDON, IN 1890.

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Half the London bridges were built, or rebuilt, during this period. Waterloo Bridge was begun in 1811, and completed by its designer and architect, John Rennie, on the 18th of June, 1817, having cost upwards of a million sterling. It is not only the longest of the Thames bridges, but was pronounced by Canova the finest bridge in the world, and is justly universally admired. Rennie built Southwark Bridge, an iron one, at a cost of eight hundred thousand pounds, and completed it in 1819, its erection occupying five years. Sir John Rennie, his son, built the new London Bridge from the designs of his father; but this was not begun till six years after the death of George III., nor finished till 1831, at a cost of five hundred and six thousand pounds.

Iron suspension bridges were also introduced towards the end of this reign. Chain bridges had been erected in China for nearly two thousand years, and rope bridges in India and South America still earlier. In England a foot-bridge of iron chains was erected at Middleton, over the Tees, in the middle of the eighteenth century. In 1816 a bridge of iron wire was thrown across the Gala Water; and another, on a different principle, the following year, was erected over the Tweed, at King's Meadows. But now much greater and more complete works of the kind were to be executed. Captain (afterwards Sir Samuel) Brown introduced many improvements into these structures. He substituted iron ropes for hempen ones, thereby forming cable-chains, like those used in Wales on quarry tram-roads, and these he applied to suspension bridges. In 1819 he was commissioned to construct an iron suspension bridge over the Tweed, near Kelso, called the Union Bridge, which he completed in 1820, at a cost of five thousand pounds. In 1827 the first suspension bridge was thrown over the Thames by Mr. William Tierney Clarke; and in 1818 Telford commenced his great work of throwing a suspension bridge over the Menai Strait, near Bangor, which he completed in 1825. The main opening of this stupendous work is five hundred and sixty feet wide, and one hundred feet above high-water mark. The length of the roadway of the bridge is one thousand feet. The cost was one hundred and twenty thousand pounds. This was Telford's chef-d'œuvre. But the same neighbourhood was destined to see a more stupendous structure span the Strait from the Welsh shore to Anglesey. This was the tubular railway bridge, connecting the London and Holyhead line, within view of Telford's elegant suspension bridge. This was erected by Robert Stephenson, from his own design, greatly improved by suggestions from William Fairbairn of Manchester. It was completed in October, 1850, at a cost of six hundred and twenty-five thousand eight hundred and sixty-five pounds. Further description of this great work is not proper here, as it belongs to a later date, but it seemed fit to mention it in passing, as an evidence of the progress of the engineering science in the reign of Victoria.

MENAI SUSPENSION AND TUBULAR BRIDGES. (From a Photograph by Hudson.)

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