20 



their attention (as they themselves expressed it) to ascertain 

 some standard which should be uniform and to preserve a due 

 proportion as well in its parts as in its multiples." 



Notwithstanding the defects in all these standards made in 

 the reign of Elizabeth, they continued to be used at the Ex- 

 chequer until 1825, when they were superseded by the stan- 

 dards then established by law, the standard of capacity having 

 been again replaced in 1834. 



It must be remembered that the comparison of these stan- 

 dards was conducted without any of the refinements now con- 

 sidered necessary, and I doubt if even a normal temperature 

 was defined, or if temperature was observed at all, or if the 

 effect of specific gravity was recognised in these verifications. 

 The scales and other comparing apparatus must at that time 

 have been of a crude and unreliable kind, as the results pub- 

 lished in the fifth report of the Commissioners seem to indi- 

 cate. Even in the smaller weights such large fractions of a 

 grain as the quarter and half were very doubtful quantities. 



The limit of error settled by the Commission for the one 

 ounce troy weight is the 4S T 00 , or '100 of a grain, the same as 

 for the one pound troy, which in the latter case is the 57 * uu of 

 the total weight, whereas the comparison referred to above 

 shows that the errors between the standards themselves in the 

 possession of the Exchequer amounted to, for the one ounce 

 troy, the -y^, or half a grain. 



It is specified that the balance used in modern verifications 

 of such weights as one-eighth of an ounce up to one ounce is 

 " a balance with gun-metal beams, steel knife edge, and agate 

 planes, made by Messrs. Ladd & Oertling, No. 4, to weigh from 

 one ounce to one grain, to turn with the '005 of a grain." The 

 vast difference between an observation which takes note of the 

 "005 of a grain, and that which is very doubtful about the '250 

 of a grain is significant enough. 



LENGTH. 



If we look back to the origin of weights and of mea- 

 sures of capacity (for the idea of making capacity a scien- 

 tific derivative of length or weight appears to be of very 

 modern application) we shall find nothing but confusion, and no 

 sign of concordance or system ; but if we turn our attention 

 to measures of length we shall find some indication of a natural 

 unit of length, more or less vague, but the concordance is 

 somewhat remarkable. Upon an examination of the diagram, 

 Plate VII., the idea will suggest itself that the step or human 

 stride, or the human foot, formed the basis of most of such 

 measures among the countries or nations there represented. 

 The most natural way of roughly estimating the distance from 



