No. 34. — 1887.] PEARL FISHERIES OF CEYLON. 



37 



chevvu. Then the money value follows at once from the market 

 price per chevvu at the time. 



If there be more pearls than one of the same " size " and " class," 

 they are generally weighed and valued together, and then the chevvu, 

 calculated from the weight of all these pearls together, is to be divided 

 by the number of pearls before calculation of the money value of each 

 pearl is made. 



In practice, from the nature of the small weights used, fractions of 

 different kinds would come into the chevvu calculation. To preserve 

 uniformity in such fractions, and in the results arrived at, convention 

 has established that all the fractions in the calculations be reduced, or 

 made, to have the number 320 as denominator, this number being one 

 that can, from the nature of the weights in use, arise in chevvu 

 calculations. 



The actual process, then, in use by native merchants, may be stated 

 thus :— 



i. — The weight, in manchddi, of the pearl (or pearls, if there be more 



than one of the same " size " and " class ") is reduced to a 

 fraction having 320 as its denominator. 



ii. — The numerator of the fraction is multiplied by itself, i.e., its 



square found. 



iii. — Three-fourths of the square is taken. 



iv. — The result is divided by the pearls (if there be more than one, 



as above stated). 



v. — The result is then divided twice consecutively by the number 



320, which gives, as the final result, the chevvu of the weight 

 in the form of a fraction with 320 as its denominator, as 

 required. 



vi. — And the money value then follows from the (known) market 



price of the pearl (or pearls) per chevvu at the time. 



Such is the plan followed by native pearl merchants with regard to 

 pearls of the superior " classes " above mentioned. Probably only a few 

 of these men see that all they do is simply calculating three-fourths of 

 the square of the pearls' weight. To facilitate their own operations 

 they have certain tables, constructed once for all ; and besides these, 

 something like a multiplication table to 320 times, which one may 

 sometimes hear them repeating to themselves. But all these aids are 

 quite unnecessary to anyone who can work an ordinary sum in " rule 

 of three." 



