Yi] A CEYLON PEARL FISHERY 75 



is reported to the coxswain of the boat, who records 

 the condition of bottom and 03 sters upon a diagram 

 form with which he is provided. The oysters are 

 retained in the boat for the inspector to examine. 

 The four boats, having each made a complete circuit, 

 are next ranged in line abreast in the same manner 

 as before, between the i-mile and the J-mile buoys, 

 and each then makes a second circuit. Lastly, there 

 is a third series of circles, so that the four boats 

 thus make a total of twelve concentric circuits, each 

 boat making three. The results shown upon the 

 four coxswains' diagrams are transferred by the 

 inspector to a final diagram or plan furnished 

 with twelve concentric circles. When this is done 

 the inspector possesses a graphic diagram of the 

 average distribution of old and young oysters, and 

 the places where no oysters occur at all. He cal- 

 culates in square yards the area occupied by oysters, 

 and then the approximate number of oysters thereon 

 may be estimated by taking the average number 

 of oysters per dive (ascertained by examining the 

 divers' results), in conjunction with the average 

 amount of ground which a diver is credited with 

 being able to clear at one descent. Usually this area 

 is considered to be about three square yards, and by 

 assuming this to be a maximum area the danger of 

 overestimating the number of oysters is avoided. 

 Inspection estimates are usually less than the 



