Captain Brown and Mr. Brunton – to the former, for introducing the iron cable, and combating the prejudices of the public in favour of hemp – to the latter, for perfecting the cable chain. It is impossible to anticipate the advantages which will accrue from the general adoption of iron cables. Many, many lives will be saved by this invention; not to speak of the saving of property, which, though of great importance in a national point of view, is but of secondary consideration. Such is our opinion of the safety to be derived from the use of iron in place of hemp, that we have no doubt whatever, that, were ships generally furnished with a good scope of chain, of proper weight, and of the best construction, net one instance out a hundred that now occur, of ships being lost on a lee shore, would take place. In rocky anchorage, hemp is cut to pieces in a short time in rough weather; but chain receives no other injury than that of a little rubbing or polishing, and the weight of the bight of the latter gives amazing ease to the tossing vessel – giving way to the swelling wave that elevates the ship, and then acting by its gravity to keep her as stationary as circumstances will permit.”
In July, 1817, Commander Brown obtained a patent for the manufacture of iron bridges of suspension, which are composed of straight wrought-iron bolts or bars, united at their ends by side-plates, with bolts passing through them, so that each line becomes, in effect, an entire bar, which extends over its respective piers, and is secured in the rock or ground. A bridge of this description was erected by Commander Brown, in 1813, on his premises in the Isle of Dogs: it was originally intended for foot-passengers, and weighs only 38 cwt., but its strength is such, that carts and carriages pass safely over it. The span is 100 feet.
In July, 1820, Commander Brown’s suspension-bridge across the Tweed, near Tweed-hill, was opened, and its stability proved to the satisfaction of every spectator. The following description thereof is taken from the Monthly Magazine, Aug. 1st, 1822:
