1 68 Sir George Shuckburgh Evelyn’s Endeavours 
subsisting at Paris, to whom it was sent in 1742, for the pur- 
pose of comparing the French and English measures. The 
middle line, marked Exch. of the three abovementioned, de- 
notes, as is supposed, the standard yard from the Exchequer. 
(§. 37.) This bar of Mr. Graham’s had been previously 
laid together with my scale divided by Mr. Troughton, for 
twenty-four hours, to acquire the same temperature; they 
were also of the same metal, and, by placing it under my 
microscopes, adjusted to the interval between 10 and 46 
inches, I found the interval on the Tower standard exceed 
Inches 
mine, by — 0,001 2 7^ 
,00135 
= the total length therefore 36,00130 
,00128 > inches, the thermometer at 6o°,8. 
IMfean = ,00130 
The interval on the line marked Exch. was shorter than 
Inches. 
— ,0066 
mine by 
,00 66 
= the total length = 35,9933 
0068 S. OO’WC 
\ inches, the therm, at 6o°,6. 
,0067 
And the Paris half-toise, which had been supposed by the Aca= 
demy to be = 38,355 English inches, was found, compared 
Inches. 
with mine, to be = 38,356 1 'i inches. 
,3563 |>Mean = 38,3561 * 
> 3559 
• Dr. Maskelyne says, this standard yard of Mr. Graham’s was T ^ 5U inch 
longer on three feet than Mr. Bird’s divided scale, which he generally made use of 
in all his operations of dividing ; and. from one made conformably to this of Mr. 
Bird’s, Mr. TROucHTON_divided my scale of 60 inches. This remark seems to 
