602 MISCELLANEOUS PAPERS. 



liacl fixed upon a temperature at whicli tbeir standards were to be re- 

 garded as of the true leugtb. On the return of the rod from Paris Mr. 

 Graham caused Jonathan Sisson to divide the English yard and the 

 French half toise each into three equal parts, after which the rod was 

 deposited in the archives of the Koyal Society, where it still remains.* 

 Objection having been made that the original and legal standard yard 

 of England was not the one at the Tower, but the Elizabethian stand- 

 ard at the Exchequer, the Royal Society requested Mr. Graham to com- 

 pare his newly made scale with the latter standard, and on Friday, 

 April 22, 1743, he did so in the presence of a committee of seven mem- 

 bers of the Royal Society. In the following week the same gentlemen 

 compared the Royal Society's scale with the standards at Guildhall and 

 the Tower, and also with the standards of the Clock-makers' Company. 

 These comparisons having shown that the copy of the Tower yard upon 

 the Koyal Society's scale was about 0.0075 of an inch longer than the 

 standard at the Exchequer. Mr. Graham inscribed upon the Royal So- 

 ciety's scale a copy of the latter standard also, marking it with the 

 letters Exch., to distinguish it from the former, which was marked E. 

 (English), and from the half toise which was marked F. (French). t 



In the year 1758 the House of Commons appointed a committee to 

 inquire into the original standards of weights and measures of England ; 

 and under instructions from that committee, the celebrated instru- 

 ment maker, John Bird, prepared two brass rods, respecting which the 

 committee speak as follows in their report: "And having those rods, 

 together with that of the Royal Society laid in the same place, at the 

 receipt of the Exchequer, all night with the standards of length kept 

 there, to prevent the variation which the difference of air might make 

 upon them, they the next morning compared them all and by the means 

 of beam compasses brought by Mr. Bird found them to agree as near 

 as it was possible." J One of these rods was arranged as a matrix for 

 testing end measures, and the other was a line measure which the com- 

 mittee recommended should be made the legal standard of England, 

 and which has since been known as Bird's standard of 1758. Respect- 

 ing the statement that after lying together all night the rods were all 

 found to agree as near as it was possible, Baily says: "This is some- 

 what remarkable, and requires further explanation, which unfortu- 

 nately can not now be accurately obtained. For it is notorious that 

 the measure of the yard of the Royal Society's scale differs very con- 

 siderably from the standard yard at the Exchequer: - - - Owing 

 to this singular confusion of the lengths of the measures, which does 

 not appear to have been unravelled by any subsequent Committee, it 

 has happened that the Imperial standard yard - - - has been 

 assumed nearly 1 -^ 140 of an inch longer than the ancient measure of 

 the kingdom."§ There is little difiHculty in surmising what Bird did. 

 The Exchequer standard consisted of a rod and its matrix. The Royal 



» 7, pp. 18o-'8. t P, i)p. 541-550. t 13, p. 434. § 37, p. 43. 



