232 
PROFESSOR 0. REYNOLDS ON THE THEORY OF LUBRICATION 
which, when T = 5‘83°, N=150, 17=337, rt=l - 25, being substituted in equation 
K 3 =— 0-1665 
f =446 .(167) 
In Mr. Tower’s Table IV., it appears that with brass No. 1, mineral oil, 
N=150 17 = 310 /'=4-4 L'=415 /'=* 51 
whence interpolating for 
L' = 337 
/' = 4-58. .(168) 
This agreement is very close, for taking account of the difference of radius, the 
calculated friction for brass No. 2 should have been about ’95 of the measured friction 
with brass No. 2. 
In order to show the agreement between the calculated pressures and those of Mr. 
Tower, the values of - for c=’5 have been plotted, and are shown in Plate 8, 
figs. 2 and 3, the crosses indicating the experiments with brass No. 2, as in Table \ II. 
(Tower). 
43. Conclusions. 
The experiments to which the theory has been definitely applied may be taken to 
include all Mr. Tower’s experiments with the 4-inch journal and oil bath, in which 
the number of revolutions per minute was between 100 and 450, and the nominal 
loads in lbs. per sq. inch between 100 and 415. The other experiments with the oil 
bath were with loads from 415, till the journal seized at 520, 573, or 625 ; and a set 
of experiments with brass No. 2 at 20 revolutions per minute. All these experiments 
were under extreme conditions, for which, by the theory, c was so great as to render 
lubrication incomplete, and preclude the application of the theory without further 
integrations. 
The theory has, therefore, been tested by experiments throughout the entire range 
of circumstances to which the particular integrations undertaken are applicable. And 
the results, which in many cases check one another, are consistent throughout. 
The agreement of the experimental results with the particular equations obtained 
on the assumption that the brass, as well as the journal, are truly circular, must be 
attributed to the same causes as the great regularity presented by the experimental 
results themselves. 
Fundamental amongst these causes is, as Mr. Tower has pointed out, the perfect 
supply of lubricant obtained with the oil bath. But scarcely less important must 
have been the truth with which the brasses were first fitted to the journal, the 
