the Suhject of Wtighls and Measures. 179 



of water or other liquid which a vessel may be inade to contain 

 when its brim is thoroughlv dry, and that wliich it will hold with- 

 out running over, wlien its edges have been moistened. 



" The system of weights uiav be carried on to any extent with 

 great accuracy, from those of the ounce, half-])ound, and pound, 

 by means of the process invented by Rorda, and called by the 

 French la melhode des doubles pesces, the only method with which 

 we are acciuainted that is entirely independent of friction and of 

 inequality in the anus of the balance*. In extending the avoir- 

 dupois system, we think the " long hundred" or" hundred weight" 

 of 112 lbs., and its quarter, should be entirely rejected; not 

 merely because the number 7 enters the constituent factors 4, 7, 

 and 4 ; but because its use is absolutely contrary to law. Tiie 

 common hundred of 4 times 25, but distinguished by some other 

 name, would be far preferable. 



" With the awkward divisions and denominations of the wool- 

 dealers, we know not what to do. Whetlier they shall be re- 

 tained or rejected is a question of expediency. Troy- weight must, 

 we apprehend, be allowed to the goldsmiths and jewellers : the 

 ratio (oyt) to 7^0) of its pound to the avoirdu|jois poui.d is well 

 ascertained. The use of grains, scruples, drachma, &c. must, 

 doubtless, be allowed as heretofore to the apothecaries. 



" We have now, we trust, brought the results of this long, and, 

 in some respects, intricate inquiry, into a shape that is both prac- 

 tical and scientitic. No deviation from existing measures is re- 

 commended but where there is palpable irregularity or extreme 

 fluctuation ; and the several standards of length, capacity, and 

 weight, are mutually coiuiected by jjrinciples which, while they 

 are calculated to satisfy the philosopher, are within the compre- 

 hension of all men of moderate intellect and information. A sy- 

 stem of such gentle but effectual reformation as we have sketched, 

 may, we conjecture, be introduced without affecting the real in- 

 terests, or violently shocking the prejudices, of any class of men. 

 It remains that wesay a little resj)ecting the legislative means by 

 which this maybe best ensured. 



* In order to ascertain the wci.^^lit of ii body, W, by this method, jjlace 

 it in one of tlie jjlutts or basins, )i, of tlie balance, and produce an equili- 

 brium by l>uttinf,' certain bodies in the other basin, IV. I5cgin, for example, 

 by placing heavier .substanccLi in IV, sucli as maybe known lo a])proach to- 

 wards W in wcif^ht. Then place .successively in the basin 15' bullets smaller 

 shot, minute fragments of sheet copper, tlien of paper, i^c, till the tonjjne 

 <jf the balance i:; bniufjlit permanently to the vertical position : this evidently 

 indicates the hori/.ontaiity of tlie arm's of the balance. Then ^.rently remove 

 the ;;iven body \V, and substitute for it in the iiasin H, such weitjhts, shot, 

 fra;;ments of paper, ike. as will to^'etli-r fstore the balance to the hori- 

 zontal position: the a!^/,'regate of these will correctly express the weight of 

 the body \V, in whose place ihcy have becu substituted. 



M2 "Here, 



