various British standards of linear measure. 8 g 
thousandths of an inch. In Sir George Shuckburgh’s “ac- 
count of experiments for determining a standard of weights 
and measures,” he remarks, that there existed another stand- 
ard yard made by Bird, in the year 1760, which did not 
differ more than two ten-thousandths of an inch from the 
standard of 1758; but he does not say whether this differ- 
ence was observed to be in excess or in defect: 
As it was possible that this standard yard of 1760, might 
coincide with 36 inches of Sir George Shuckburgh's scale, 
I was anxious to compare them together, and by the exer- 
tions of Davies Gilbert, Esq. M. P. the standard of 1760 
was found in the custody of the House of Commons, and con- 
fided to my care. It is (as Sir George Shuckburgh observed) 
precisely similar in form to the standard of 1758, the yard 
being marked by two dots upon gold pins, which, though 
very large, are in tolerable preservation. 
The five standard scales which I have just described, were 
placed together on the 15th of June, 1820, and arranged so 
that those of least bulk should be farthest from me during 
the observations, as they would be more readily affected by 
the proximity of the person of the observer. 
As I was desirous that comparisons of such importance 
should not rest wholly on my own authority, I requested 
Dr. Wollaston to take two series of measurements, which, 
together with my own, are contained in the following table. 
MDCCCXXI. 
N 
