Page:Dictionary of National Biography volume 07.djvu/152

 of the timber from one part of the yard to another. He also devised and erected machinery for the manufacture of shoes, which were adopted by government for use in the army; but the peace of 1815 involved him in heavy pecuniary loss on his contracts. In 1812 Brunel made his first experiments in steam navigation on the Thames with a double-acting marine engine, and interestedhimself greatly in establishing a line of steamers to ply between London and Margate. Two years later he prevailed upon the navy board to accept his proposals for towing vessels of war to sea by the aid of steamtugs, and made at his own expense a number of experiments directed towards the construction of steam vessels of suitable size, capable of heading heavy seas, and carrying all necessary gear. But the navy board, after nearly six months’ deliberation, revoked their acceptance and repudiated the indemnity which they had promised Brunel for the expenses he had incurred, on the ground that the attempt was ‘too chimerical to be seriously entertained.' About this time Brunel took out patents for several inventions of minor importance, which might have brought considerable prodt to him had his commercial faculties and opportunities been proportionate to his scientific ability. In 1816 he invented an ingenious knitting machine, and two ears later patented two preparations of tingxil for purposes of ornamentation, which had an extensive application. In 1819 he took out a patent for improvements in stereotype plates for printing, and negotiations were entered into with the proprietors of the ‘Times’ and the ‘Courier’ for the adoption of his invention. An agreement was concluded with the ‘Times,' but was subsequently abandoned. In 1820 he was invited to furnish designs for a bridge over the Seine at Rouen, and in the same year he prepared plans for a timber bridge of 880 feet span to be thrown across the 'eva at St. Petersburg; but neither of these proipctswas carried into execution. His designs, owever, for bridges to be erected in the island of Bourbon, to withstand the violent hurricanes which prevail there, were accepted by the French government and carried into elfect.

In 1814 Brunel‘s sawmills at Battersea were nearly detroyed by fire. From this time, owing to financial mismanagement, the prosperity of the undertaking steadily declined, until, in 1821, a crisis occurred, and he was thrown into prison for debt. After some months spent in the king’s bench he obtained from the government, at the instance of many influential friends, a grant of 5,000l. for the discharge of his debts, and was then liberated. During the next four years Brunel designed sawmills for the islands of Trinidad and Berbice. He effected improvements in marine steam-engines and addle-wheels. In 1823 he supplied plans for swing-bridges for the docks at Liverpool, where three years later he introduced the Boating landing-piers which have since been so largely extended. His opinion was taken on many of the engineering projecta of the day; while he at this time was perseveringly engaged in experiments, in which he sacrificed much time and money, for the production of a new motive power from the vapour of gases liquefied at a low temperature. He constructed and patented a machine to carryout this principle, but it had no practical success, and the plan was ultimately abandoned.

Brunel’s energies were now almost exclusively devoted to the construction of the Thames tunnel. It is said to have originated in a plan peroposed by him in 1818 for establishing tween the banks of the Neva communication independent of the Hoating ice. In 1824, under the auspices of the Duke of Wellington, a company was formed to carry out the scheme (proposed by Brunel for boring a tunnel un er the Thames from Rotherhithe to Wapping. He suggested the excavation of a passage of a size to admit a double archway of full dimensions at once, without the preliminary construction of a driftway; and he utilised for this purpose an apparatus forwhich he had taken out a patent in 1818. This consisted of a large shield covering the total area to be excavated, and composed of twelve separate frames, comprising together thirty-six cells, in which the miners worked independently of one another; the whole machine capable of bein forced forward by screw power as the work advanced. The operations were begun at Rotherhithe on 16 Feb. 1825, and, in the face of the enormous difficulties that were encountered, were not finally completed till the end of 1842. Panics and strikes took place among the workmen. In 1827 an irruption of the river occurred, which was stopped by bagsof clay. In 1828 there was another irruption, and in August of that year the works were stopped, and the tunnel remained bricked up for seven years. After the resumption of the undertaking there Were, in August and November 1837 and March 1838, three more irruptions, and it was not till March 1843 that the tunnel was opened to the public, Brunel met these disasters with characteristic fertility of resource, and persevered in the work with untiring energy. But the strain upon his mind produced an attack of partial paralysis,