When the ingenious Miss Pardoe visited Constantinople in 1836, she was not less surprised than gratified by the inquiry of an Albanian chief, as to the probable completion of the Thames tunnel. This, however, is but one of the many instances of the anxiety with which the great work was watched throughout continental Europe. In Egypt, too, where a new country is rising, phoenix-like, upon the ashes of the old world, the progress of the tunnel was regarded with like curiosity; participated, indeed, throughout the civilised world. This interest is fully attested by the visitors' book at the Tunnel, wherein are inscribed the names of scientific men belonging to nearly every city of importance. The engineer of this great work, Mr. (afterwards Sir) Mark Isambard Brunel, completed his design in 1823; and amongst those who then regarded it as practicable were the Duke of Wellington and the late Dr. Wollaston. The works were commenced in 1825, and the Tunnel itself in 1826; and by March, 1827, it had advanced about one-third of the whole length. All proceeded well till May 18, when the river burst into the Tunnel with such velocity and volume, as to fill it in fifteen minutes; but, although the men were at work, no lives were lost. The hole, thirty-eight feet deep, was closed with bags of clay and hazel-rods, the water pumped out, and the works resumed in September. On Jan. 12, 1828, the river broke in a second time, and filled the Tunnel in less than ten minutes; when the rush of water brought with it a strong current of air that put out the lights; six of the workmen were lost. For some distance, Mr. Brunel, junior, struggled in total darkness, and the rush of the water carried him up the shaft. The Tunnel was again cleared, and the part completed found to be sound. Hundreds of plans were proposed for its completion; the funds of the company were too low to proceed, and above 5000l. was raised by public subscription.

For seven years the work was suspended; but, by advances from Government, it was resumed in 1835. On April 23, 1837, there was a third irruption of the river; a fourth on Nov. 2, 1837, with the loss of one life; and, on March 6, 1838, the fifth and last irruption took place. Thus, of the tunnel there were completed—

Meanwhile, the tunnel works proved a very attractive exhibition. In 1838, they were visited by 23,000 persons, and, in 1839, by 34,000. By Jan. 1841, the tunnel was completed from shore to shore—1140 feet, and Sir I. Brunel, on Aug. 13, was the first to pass through. On March 25, 1843, the tunnel was opened to the public, with a demonstration of triumph.

The cost of the work has been nearly four times the sum at first contemplated; the actual expense being upwards of 600,000l. These, of course, are but a few data of the great work, the progress of which, for twenty years, interested every admirer of scientific enterprize. The engineering details present marvels of ingenuity. The building of the vast brick shaft, 50 feet in diameter, 42 feet in height, and 3 feet thick, with, set over it, the steam-engine for pumping out the water and raising the earth—and the sinking of the whole, en masse, into the Rotherhithe bank, were master-works of genius. Thus far the vertical shaft: the tunnel itself commenced with an excavation larger than the interior of the old House of Commons. But the great invention was the shield apparatus—the series of cells, in which, as the miners worked at one end, the bricklayers formed at the other the top, sides, and bottom of the tunnel. The dangers, too, were many: sometimes, portions of the frame would break, with the noise of a cannon-shot; then alarming cries were heard, as some irruption of earth or water poured in; the excavators were, however, much more inconvenienced by fire than water—gas explosions frequently wrapping the place with a sheet of flame, and strangely mingling with the water, and rendering the workmen insensible. Yet, with all these perils, but seven lives were lost in making the tunnel under the Thames; whereas, nearly forty men were killed in building the new London Bridge.—Note-book of 1848.