456 Major-General Roy’s Account 'of the 
that of glafs being taken into- the account, it appears, that the 
fniall ex pan lion * of the deal rods from the humidity of the. 
air, muff, at this point, have exceeded what it was eftimated 
at in the general table by 0.931 of a v n inch, lu pooling no error 
of any kind whatever to have a rife n in the execution, from, 
bringing the rods into contact, or otherwjfe. 
On Saturday the 2 1 ft of Augufl, the meafurementr was, 
refumed at the thirty-ninth fiat ion, and continued for five hypo- 
thenufes to- the thirty-fifth in cl 11 five.. 
This day, about noon, his majest y deigned to honour thet 
operation by M-fs prefence, for the fpace of two hours, enter- 
ing very minutely into the mode of conducing it, which met 
with his gracious approbation. 
On Monday the 2,3d, the menfuration was farther continued 
for five hypothenufes,. that is,, to the thirtieth inclufive. 
O11 Tucfday the 24th, we proceeded with the measurement: 
for the fpace of feven hypothenufes, finifhing the bufinefs ofr 
the day at the twenty- fecond ffati.011. 
In. 
" -fr 0.383 for 1° excels of temperature of the brafs fcale from. 
* 1 55 deal rods 62° to 63°. 
= 3100 feet, -j- 0.65 1 proportionable part of the eflimated expanfion from- 
v humidity. 
-f 1*034 equation, of the deal rods on 3100 feet-. 
155 glafs rods 
073100 feet 
" 4*2,301 for 6° excels- of the heat of the brafs fcale from, 
62“ to 68°. 
< —^0.436 obferved contradion of the glafs from the 11th and: 
1 2th columns of the table. 
.-p 0.100 by which tbe 155th rod fell fhort of the thread. 
4- 1.965 equation of the glafs rods on 3100 feet. 
©.931 
Difference of the two equations, underrated in the 
expanfion of the deal jods^. 
