Page:Professional papers on Indian Engineering (second series).djvu/103

 No. CCXCV.

THE “CHIN CHIA” OR CHINESE CHAIN-PUMP IN THE LARUT TIN MINES.

[Vide Plate].

By P. Doyle, Esq., C.E., F.S.S., M.R.A.S., Superintendent Public Works, Surveys, and Mines, Perak.

The mines are quarries or entirely open excavations, from 10 to 25 feet deep, through comparatively porous soils, and the spring level of the country being only six feet below the surface of the ground, the percola- tion of water into the workings is very great indeed, due chiefly to the high rainfall, which averages 150 inches, distributed pretty evenly through- out the year, and the numerous water-courses intersecting the mines, which are required for turning the water-wheels working the pumps en- gaged in draining.

The following description will, it is anticipated, sufficiently explain the accompanying diagrams, affording all needful information anent the ar- rangement and details of the different parts of the machine.

The chain-pump in use by the Chinese in the Larut mines is only a modification of appliances long known in Europe and the East. It con- sists of a wooden gutter or working barrel, placed at an angle which seldom exceeds 20°. A fair average of the existing grades is 1 in 6. The gutter or trough is from 12 to 16 inches high, and from 4 to 6 inches wide, and of lengths ranging up to 100 feet, composed of three single planks. A few inches above, and supported by framing attached to the sides, a fourth plank or platform runs for the full length parallel 61