312

HISTORY OF ENGINEERING.

Book I.

cubic yards of water per minute to the height of 33 feet, and consumed two bushels ofcoals per hour; it turned a drum bearing an endless chain, which glided in an horizontaldirection upon rollers, and passed over a second circular drum ; to which was attached aueccentric pin, the action of which raised the piston of a powerful pump.

In order to prevent the links of the chain from becoming loose by their expansion, and tomake them always press equally upon the two drums, so that they should transmit andreceive motion from each other, there were two parallel upright posts, between which thechain passed; here was introduced a heavy roller, which mounted or descended in groovesand rested on the upper part of the chain, thus, by its constant weight, exerting an equaltension on the two drums.

There are two capacious docks; the western covers an area of 20 acres, being 420yards long, and 320 yards wide. The eastern dock has an area of about 7 acres. Theentire area within the boundary walls of the whole is a little more than 71 acres.

The tobacco warehouses, on the north side of the tobacco dock, which is more than anacre in extent, are the largest and most convenient to be met with. They cover 5 acres ofground, and will contain 24,000 hogsheads of tobacco.

The vaults under the warehouses include an area of 18 acres, and can admit 6000 pipesof wine.

East India Docks were erected after the passing of the act in July, 1803, which au-thorised the formation of a company consisting of thirteen directors, elected in fourths every

IMPORT DOCK-

EXPORT DOCK

Fig.316.

EAST INDIA DOCKS.

year. Every fourth year four nominations are made instead of three: each director topossess at least twenty shares, and four to be directors of the East India Company . Thegeneral interests and accounts of the company are laid before two meetings, held inJanuary and July every year. Persons who do not possess five shares are not allowed tovote.

The import dock contains 19 acres, the export nearly 10 acres, and the basin 3 acres;the two docks are connected with the basin by two short locks, making a total superficies of32 acres. The depth of these docks, measured from the levels of the quays, is 27 feet.

Vessels enter from the Thames by a lock opening in the west side of the basin, overwhich is a light iron bridge, 4 feet in breadth, for foot passengers.

The import dock is 1410 feet in length, and 560 feet in breadth. The export dock is 760feet in length, and 463 feet in breadth.

The various works were executed under the direction of Mr. Ralph Walker andMr. John Rennie .

Fronting the river is a quay nearly 700 feet in length, and the export dock has a loftybuilding in which is machinery to mast or unmast the largest vessels.

Since the dissolution of the East India Company as a commercial corporation, thesedocks have been opened to vessels from all parts of the globe.