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Diamond Mine (Being stopped just below)

being stopped, just below the head of the canal, by an embankment formed of several thousand bags of sand. This is a work of considerable magnitude, and requires the co-operation of all the negroes to complete it; for the river being wide and not very shallow, and also occasionally subject to overflow, they have to make the embankment so strong as to resist the pressure of the water, admitting it to rise four or five feet. "The deeper parts of the channel of the river are laid dry by means of large caissons or chain-pumps, worked by a waterwheel. The mud is then carried off, and the cascalhao is dug up, and removed to a convenient place for washing. This labour was, until lately, performed by the negroes, who carried the cascalhao in gamellas on their heads; but Mr. Camara has formed two inclined planes, about one hundred yards in length, along which carts are drawn by a large water-wheel, divided into two parts, the ladles or buckets of which are so constructed, that the rotary motion may be altered by changing the current of water from one side to the other; this wheel, by means of a rope made of untanned hides, works two carts, one of which descends empty on one inclined plane, while the other, loaded with cascalhao, is drawn to the top of the other, where it falls into a cradle, empties itself, and descends in its turn. At a work called Canjeca, formerly of great importance, about a mile up the river on the opposite side, there are three cylindrical engines for drawing the cascalhao, like those used in the mining country of Derbyshire, and also railways over some uneven ground. This was the first and only machinery of consequence, which I saw in the diamond district, and there appear many obstacles to the general introduction of it. Timber, when wanted of large size, has to be fetched a distance of one hundred miles, at a very heavy expense; there are few persons competent to the construction of machines, and the workmen dislike to make them, fearing that this is only part of a general plan for suspending manual labour. "The stratum of cascalhao consists of the same materials with that in the gold district. On many parts, by the edge of the river, are large conglomerate masses of rounded pebbles cemented by oxide of iron, which sometimes envelop gold and diamonds. They calculate on getting as much cascalhao in the dry season, as will occupy all their hands during the months which are more subject to rain. When carried from the bed of the river whence it is dug, it is laid in heaps, containing apparently from five to fifteen tons each. "Water is conveyed from a distance, and is distributed to the various parts of the works by means of aqueducts constructed with great ingenuity and skill. The method of wash-