[ 547 ] 
Rule. All he therefore thinks pofiible, and that he 
has found he could feveral times together, under the 
fame or like Circumftances, be confident in, is to 
take fuch Meafures to about the 1 6ooth Part of an 
Inch. 
We fhall, however, in what follows, give thofe Mea- 
fures as they actually did come out, in Revolutions, 
Divifions, and Tenths: All which are alfo, for the 
Convenience of the Reader, in a fecond Column, 
reduced to the common Decimals oi an Inch 5 and, in 
a Third, to the Vulgar Fractions of the fame. 
It may further be noted, that the abfolute Quan- 
tity of all Meafures, any ways infcribed on Standards 
of Metal, mull:, from the Nature of Things, vary with 
the Alterations in the Heat or Coldnefs of the Wea- 
ther ; and, for that Reafon, the exad Proportion be- 
tween any Two Standards, taken at different times, 
cannot be expe&ed to be found the fame to the mod 
perfect Degree of Exad nefs, unlefs the T emperature of 
the Air fhall at thofe different times have been the fame, 
or that a proper Allowance has been made for the 
Alteration of it. Yet, in the prefent Cafe, as all the 
feveral Meafures referred to, are infcribed on the 
fame Metal, Brafs, as none of the Differences we are 
concerned about are very great, and as the Change of 
the Weather was not very confidetable between the 
Days of Trial ; it has been thought this laft Confi- 
deration might fafely be negle&ed, in fetting down 
the following Particulars. Which are, that 
The greateft Length of the -j 
Matrix of the TardMea- I Rev. Div. 
Jure , at the Exchequer, >0 : 8,2 = .0102 = 
exceeded the fquare I 
Standard Tard by - . 
B b b b 2 
The 
