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248 Mr Stevensoh's Description of Bridges of Suspension* 
months for its erection ; while a stone-bridge must have been the 
work of about three years. This work was designed and exe- 
cuted by Captain Samuel Brown, of the Royal Navy, who has 
so successfully introduced the use of the chain-cable into the 
Navy and Mercantile marine. 
The roadway of this bold design is made of timber, on which 
iron cart-tracks are laid for the carriage wheels. It is 18 feet 
in width, and is no less than 361 feet in length. The main 
beams or joisting measures 15 inches in depth, and 7 inches in 
thickness. The timber cleading or planks are 12 inches in 
breadth, and 3 inches in thickness. This great platform is su- 
spended at the height of 27 feet above the surface of the sum- 
mer water of the river. It is also made to rise about 2 feet in 
the centre, and is finished on each side with a cornice of 15 
inches in depth, which adds to its ornament, and gives it an ad- 
ditional appearance of strength. 
The roadway is suspended from the catenarian or main chains 
by circular rods of iron, which measure 1 inch in diameter. 
These perpendicular rods are wedged into caps or pieces of cast- 
iron, called Saddles, which are placed at the distance of 5 feet 
apart, and are made to rest upon the shackles or joints of the ca- 
tenarian chains, as shewn in the connecting diagram, marked c. 
Fig. 4. The attachment of the lower ends of these rods to the 
beams of the platform which they pass through, is by their em- 
bracing a bar of iron which runs along the whole extent of the 
bridge under the beams of the roadway, on each side. These 
bars measure 3 inches in depth, and they are connected with the 
suspending rods by a spear or bolt, which, in a very simple man- 
ner, completes the connection of the roadway with the perpen- 
dicular suspending rods, and catenarian chains. 
The catenarian chains of this bridge are twelve in number, 
ranged in pairs ; the one pair being placed over the other, be- 
tween the points of suspension on each side of the bridge. These 
chains, and indeed the whole of the iron-work, is made of the 
very best Welch iron. The chains are worked into a circular 
form, and measure about 2 inches in diameter. The Links, as 
they may be termed, consist of rods of 15 feet in length, and 
have bolt-holes, which are strongly welded, and neatly finished 
at each end. These links or rods are connected together by 
