( 222 ) 



about a mile up the river on the opposite side, there are three 

 cjhndrical engines for drawing the cascalhao, Hke those used in the 

 mining country of Derbyshire, and also rail-ways over some un- 

 even ground. This was the first and only machinery of consequence 

 which I saw in the diamond district, and there appear many ob- 

 stacles 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 expence ; there are few persons competent to the construc- 

 tion of machines, and the workmen dislike to make them, fearing 

 that this is only part of a general plan for superseding 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. Tbey 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 washing for dia- 

 monds at this place is as follows : — A shed is erected in the form 

 of a parallelogram, twenty-five or thirty yards long and about fif- 

 teen wide, consisting of upright posts which support a roof thatched 

 with long grass. Down the middle of the area of this shed a current 

 of water is conveyed through a canal covered with strong planks, 

 on which the cascalhao is laid two or three feet thick. On 

 the other side of the area is a flooring of planks, from four to 

 five yards long, imbedded in clay, extending the whole length 

 of the shed, and having a slope from the canal, of three or four 

 inches to a yard. This flooring is divided into about tweiit3' 

 compartments or troughs, each about three feet wide, by means of 

 planks placed on their edge. The upper ends of all these troughs 



