'proposed to be erected at Montrose , 
21T 
Edinburgh , 18 tli February 1824. 
Having, in pursuance of the request of the Commissioners, 
again considered the subject of the above Heport, I see nothing 
material to alter in any part of the design therein contained. I 
magnificent work. Not feeling myself, however, at liberty to publish all the 
particulars which were obligingly communicated to me by Mr Rhodes, the su- 
perintendant of the iron-work, and by Mr Hazledean, the contractor, I may 
just state generally, that the span of this arch is 580 feet ; depth of arch 50 
feet ; height of pillars above roadway 53 feet ; and height of roadway above 
the level of high water 100 feet, so that vessels may sail under the bridge. 
Base of pillars founded on rock near the level of low water, so that, from the 
base to the top of each suspending pillar, the height is no less than 100 feet. 
Between these pillars and the high ground, on the opposite shores, the space 
is made up by three stone arches on the W elsh, and four on the Anglesea side of 
the strait ; and it is only the middle space of 580 feet that is proposed to be span- 
ned by means of the hanging arch. This is to consist of sixteen distinct sets of 
main-chains, ranged in a manner peculiar to this bridge. Instead of having two 
compound chains, one on each side of the bridge, and a clear roadway between 
them, there are here, between the outside chains, two others, of the same di- 
mensions, in the middle ; and these middle chains are connected to the road- 
way by upright suspending rods, in the same manner as the external ones ; 
so that the whole roadway is divided longitudinally into three compartments, 
the middle one of which, of 4 feet wide, is intended for foot passengers, and the 
two exterior ones, each 1 2 feet wide, for carriages, the one for going, the other 
returning. The object of this arrangement of the chains and rods, is to reduce 
the distance of the bearing points for carrying the roadway. The whole sus- 
pending arch, therefore, consists of four compound chains ; and each of these 
consists of four of the above-mentioned distinct sets of main-chains, ranged one 
above the other, with about 12 or 15 inches between them. Each set of chains 
is further composed of six separate chains, formed of square bars of malleable 
iron, 10 feet long, 3 inches deep, and 1| inch thick, worked up to a high state 
of refinement by repeated heating and hammering. These are swelled out flat 
at their extremities, and a hole or eye, 3 inches diameter, drilled through each 
end. These bars are united by short links, the eyes of which are also bored 
out of the solid, the object of which is to avoid welding the iron, and also by 
the squareness of the hole, and flatness of the links, to obtain a more equal bear- 
ing on the bolts. There is in all the chains together, a section of iron of 330 square 
inches. The chains are bent over the pillars at the same angle with which 
they hang on the arch. They take the ground at about 380 feet on each side 
of each pillar ; there they are bent at an angle, and carried, in a sloping direc- 
tion, 40 feet, into a square tunnel, driven out of the solid rock, and at the 
bottom of which they are made fast to strong cast-iron plates butting against the 
rock. The pillars are of mason work, and, like the rest of the arches, are 
built of a hard and very beautiful limestone rock, which abounds in the neigh- 
bourhood. In the bridge it has somewhat the look of granite, and gives the 
