ClIAl*. VIII.

BRITAIN.

511

was removed by small vessels from the Bay of Beaumaris to Bangor Ferry, a distance of 12miles.

The iron was all of the best Shropshire manufacture, supplied from Upton Forge, byMr. Hazeldine of Shrewsbury . The bars were repeatedly drawn between cast-iron rollers,grooved in various shapes, and afterwards proved at the works, previous to being shippedfor the Menai Straits.

An accurate and powerful machine was used for proving each bar, which was tested by astrain of 11 tons to every square inch of transverse section ; during the trial, it wasfrequently struck by a hammer, and its length was observed by an unvarying iron gauge.After proof, each piece of iron was cleansed, put into a stove, at a gentle heat, and thenimmersed in a trough containinglinseed oil, where it remained for ashort time, and was again returnedto the stove, when, after drying, itcame out covered with a varnish,upon which a coat of oil paint wasadded, and it was sent off to theworks. «

Iron work. — There are four setsof main chains, each composed offour: so that there are altogether16 chains, which have a similar anduniform tension. Each consists of 5chain bars in length, each 10 feetlong, 3J inches wide, and 1 inch inthickness, with 6 chain plates at eachend 16 inches long, 8 inches broad,and 1 inch thick ; the joints beingsecured by 2 bolts weighing cwt.

In the cross section of the chainthere are 80 chain bars, and thenumber there in one chain is 935, inthe sixteen, 14,960.

The entire length of the chains is1710 feet from where they are fastened to the rock on each side.

The number of chain plates to each chain is 1122, in all 17,952; each chain has 374 bolts,amounting in all to 5984.

= (©) ( 4 = 0 ;C e =0

Fig 514.

t*PPER LINKS AND JOINTS,

E

Fig. 515.

FOR TIGHTENING THB MAIN CHAINS.

ELEVATION OK CHAINS,

The vertical rods suspended from the chains are placed 5 feet distance apart, and arc1 inch square; there are 199 to each line, and in the whole four lines 796. These carry