AND ITS APPLICATION' TO ME. B. TOWLE’S LXPEEIMENTS. 231 
by equation (150) 
_ 66’08fi— 0665Tm 
~ ?d(l + 002L) 3 
whence 
a/= 000001088e~' 0665 T “.(103) 
and taking T m the same as with brass No. 1, and olive oil at N=180, i.e., 5'83° Fain - ., 
with brass No. 2, at 70'5° Fahr. 
instead of with brass No. 1’ 
a x — 00080 
> 
a u = 00077 
(164) 
The difference in the radii of curvature of the two brasses, the one deduced from 
the measured friction, the other deduced from the measured differences of pressure at 
different positions round the journal, come out equal within Tcfoooth part of an inch, 
and the values of a differing only by 11 per cent. Had the frictions been given with 
brass No. 2, this agreement would have afforded an independent comparison of the 
values of a. As it is, the only probability of equality in these two brasses arises from 
the probability of their having been bedded in the same way. 
In deducing the value a for brass No. 2, it has been assumed that the oil, which was 
mineral, had the same law of viscosity as the olive oil. Both these oils were used with 
brass No. 1, and the results are nearly the same, the mean resistances, as given by 
Mr. Tower, are as 0'623 to 0'654, or the viscosity of the mineral oil being 0‘95 that 
for olive oil ; had this been taken into account, the value of a z for brass No. 2 would 
have been still nearer that for brass No. 1, being '00084 as against '00077. 
As the radii of the two brasses seem to be so near, and as the resistance was 
measured for brass No. 1 under circumstances closely resembling those of the 
experiment with No. 2, a further test of the exactness of the theory is furnished by 
comparing the calculated friction with brass No. 2 with that measured with brass 
No. 1, with the same oil, the same speed, and nearly the same load. 
As in equation (158) 
-f =2'3773K 3 +l'37(n-l)K 2 ....... (165) 
—K a =-21^N 
z a 
Whence, taking account of the values of p, for mineral and olive oils, and the values 
of a for brass No. 1 and No. 2 for mineral oil and brass No. 2, K a has 0 '871 of the 
value in equation (150) 
'871 x '0034e — 0443T > 
* - (l + ‘002L> 
(166) 
