538 ANNUAL REGISTER, ISIS. 



it is laid in heaps containing ap- 

 parently from five to fifteen tons 

 each. 



Water is conveyed from a dis- 

 tance, and is distributed to the va- 

 rious parts of the works by means 

 ©f aqueducts, constructed with 

 great ingenuity and skill. The 

 method of washing for diamonds 

 at this placeis as follows : — A shtd 

 is erected in the form of a paral- 

 lelogram, twenty-tive or thirty 

 yards long, and about fifteen 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 co- 

 vered 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, im- 

 bedded in clay, extending the 

 whole length of the shed, and hav- 

 ing a slope from the canal, of 

 three or four inches to a yard. 

 This flooring is divided into about 

 twenty compartments or troughs, 

 each about three feet wide, by 

 means of planks placed on their 

 edge. The upper ends of all these 

 troughs (here called canoes) com- 

 municate with the canal, and are 

 so formed that water is admitted 

 into them between two planks that 

 are about an inch separate. Through 

 this opening the current falls about 

 six inches into the trough, and may 

 be directed to any part of it, or 

 stopped at pleasure by means of a 

 small quantity of clay. For in- 

 stance, sometimes water is required 

 only from onecorneroftheaperture, 

 then the remaining part is stop- 

 ped ; sometimes it is wanted from 

 the center, then the extremes are 

 stopped ; and sometimes only a 



gentle rill is wanted, then the clay 

 is applied accordingly. Along the 

 lower ends of the troughs a small 

 channel is dug to carry oft' the 

 water. 



On the heap of cascalhao, at 

 equal distances, are placed three 

 high chairs for the oflicers or over- 

 seers. After they are seated, the 

 negroes enter the troughs, each 

 provided with a rake of a peculiar 

 form and short handle, with which 

 he rakes into the trough about fifty 

 or eighty pounds weight of cascal- 

 hao. The water being then let in 

 upon it, the cascalhao is spread 

 abroad and continually raked up to 

 the head of the trough, so as to be 

 kept in constant motion. This 

 operation is performed for the 

 space of a quarter of an hour ; 

 the wafer then begins to run 

 clearer, having washed the earthy 

 particles away, the gravel-like mat- 

 ter is raked up to the end of the 

 trough ; after the current flows 

 away quite clear, the largest stones 

 are thrown out, and afterwards 

 those of inferior size, then the 

 whole is examined with great care 

 for diamonds. When a negroe 

 finds one, he immediately stands 

 upright and claps his hands, then 

 extends them, hold the gem be- 

 tween his fore- finger and thumb; 

 an overseer receives it from him, 

 and deposits itin a gamella or bowl, 

 suspended from the center of the 

 structure, half full of water. In 

 this vessel all the diamonds found 

 in the course of the day are placed, 

 and at the close of work are taken 

 out and delivered to the principal 

 ofHcer, who, after they have been 

 weighed, registers the particulars 

 in a book kept for that purpose. 



When a negro is so fortunate as 

 to find a diamond of the weight 



of 



1 



