Engineering Wonders of the World
Volume I

246 ENGINEERING WONDERS OF THE WORLD. ARAB SAILING-BOATS PASSING A DREDGER IN THE CANAL NEAR KANTARA. structions of the authorities at Cairo. These men were forced labourers. They had been sent to work on the Canal by the orders of the Khedive, much against their own wishes. It looked as if this sudden withdrawal of labour would wreck the whole scheme. The engineers, however, were equal to the emer- gency. They hired as many fellahs as they could, and superseded manual labour to a large extent by ordering powerful dredging machines and elevators of colossal dimensions. The larger machines cost £20,000 apiece, and were rightly regarded at the Huge time of their construction as Dredgers. marvels of engineering skill. The elevator was a contrivance for lifting the box of sand from the dredger and carry- ing it on to the embankment. One end of the elevator hung over the punt or barge in which, the boxes of dredgings were landed ; each, box was drawn up by a steel rope and carried on a small truck to the other end of the elevator, which, extended several yards over the embankment. On reaching that point, the end-door of the box opened, the contents emptied themselves' over the ground beneath, and the empty box then ran down the return line of wire rope back to the punt. A far more effective machine, however, was the dredger with floating conduit attachment, called by the French a couloir. This appara- tus consisted of a long mechanical duct, with a slightly inclined channel 5 feet wide and 2 feet deep, one end connected with, the dredger and the other running out desertwards over the embankment. It was supported in the middle by an iron framework on the deck of a barge. A steam-pump kept a stream of water flowing through this channel, so that when the dredged-up material fell into the upper end of the couloir, it easily ran through the duct and was cast ashore on the bank,