applicable to the Gold Bullion Assay. 105 



The weight which it is necessary to add to the cornet in the 

 pan of the balance so as to restore equilibrium, represents 

 what it has lost and what was alloy, and we may mark the 

 weight thus added not with its own real weight, but tuith 

 what is more convenient, namely, its difference from the 

 weight of the pound or unity. If ten grains or unity has 

 lost during the assay one grain, because it originally con- 

 tained that amount of silver, copper, or other foreign metals, 

 the cornet, when placed in the pan of the balance, will require 

 the addition to it of one grain weight to effect an equipoise, 

 and this one grain weight, by establishing an equipoise, will 

 signify that the cornet weighs nine grains, and that the 

 sample assayed has a fineness of *9. 



This routine would possess the anticipated advantages in 

 all cases of gold bullion of finenesses between - 8 and 1*0, 

 excepting that the fractional parts, as determined by the use 

 of the rider, have as yet no solution by its means ; the use 

 of the rider, so valuable in all appeals to the balance, need 

 not be excluded from this method, as I hope now to explain 

 by a more detailed description of the proposed method. 



First, I will describe the new set of weights : they consist 

 of a progressive series from '1 grain to 19 grains, gradually 

 rising through the series by tenth of a grain differences, 

 and, for reasons to be presently explained, they are each 

 marked as shown in the following table : — 



TABLE OF NEW SEKIES OF COMPENSATING WEIGHTS. 



Keal amount of weight 

 Mark - 



•lgr. 



•98 



•2gr. 

 •97 



•3gr. 



•96 



•4gr. 



•95 



•9 gr. 

 •9 



1-4 gr. 



•85 



1-9 gr. 



•8 



•5 gr. 

 •94 



Eeal amount of weight 

 Mark - 



•6gr. 



•93 



•7 gr. 

 •92 



•8gr. 

 •91 



1-0 gr. 



-89 



Eeal amount of weight 

 Mark - 



1-1 gr. 



•88 



1-2 gr. 



•87 



1-3 gr. 



■86 



1-5 gr. 



•84 



Eeal amount of weight 

 Mark - 



1-6 gr. 



•83 



1-7 gr. 



•82 



1-8 gr. 



•81 





There is also to be provided a rider of the real weight of -1 grain, as usual. 



All these weights, in addition to the pound of 10 grains, 

 are to be arranged on the right hand side of the balance, 



by volatilization and absorption, and there is increase of weight of the 

 cornet by a small residue of silver which the parting operation has left in it, 

 and the difference of these two opposite errors constitutes the surcharge. 



