220 
PROFESSOR O. REYNOLDS ON THE THEORY OF LUBRICATION 
Which seemed to agree very well with the reasoning Section VIII. With these 
values of the constants the values of T — were then calculated from equation (120), 
and are given in the third row in Table III. These temperatures were then substi¬ 
tuted in equation (119), and the corresponding values of f calculated, these are given 
in the fourth row, Table III. 
Table III.—Prise of Temperature in the Film of Oil caused by Friction, calculated 
by Equation (120) from Experiments with a Nominal Load 100 lbs. (see 
Table I., Tower, Art. 34). 
Nominal friction per square inch, as calculated by equation (119) from the rise of temperature. 
N 
Revolutions per minute . . . . 
100 
150 
200 
250 
300 
350 
400 
450 
o> 
Nominal friction f Table I., Toweb 
•36 
•45 
•54 
•63 
•69 
•77 
•82 
•89 
T? 
JA rn 
o 
f 
per square inch j Corrected to a 
c3 
O 
a — 
for olive oil [ curve . . . 
•33 
*55 
•55 
•63 
•705 
•768 
•83 
•89 
D O 
T-T„ 
Rise of temperature by equation 
a 
3 II 
Fahr. 
(120). 
3-45 
5-83 
8-13 
10-02 
11-77 
13-26 
14-48 
15-37 
a 
CT 1 - 
Nominal friction per square inch 
o 
P 
ca'culated by equation (119) 
J 1 
assuming c small. 
•336 
•453 
•546 
•628 
•697 
•76 
•823 
•89 
The agreement between these calculated values of f and the experimental values 
is very close; and it may be noticed that a very small variation in any of A, B and E 
makes a comparatively large difference in some one or other of the calculated values 
of or, in other words, these are the only positive values of these quantities which 
satisfy the equations. 
The only difference between the experimental and calculated values of f which is 
not explainable as experimental error, is for the lowest speed at which the 
experimental value of f is 6'7 per cent, too large. This is important as it is in 
accordance with what might he the result of neglecting c 3 , since at that speed 
c is becoming too large to be neglected, and taking c 3 into account the calculated 
value of f agrees very closely with the experimental. 
38. The Actual Temperature of the Film. 
Having found the approximate values of T m , the rise of temperature, owing to 
friction, it remains to find T x , the temperature of the film, the rise due to friction, 
so that 
T, : -{- temperature of film. 
This is found from Mr. Tower’s Table XI. (see Art. 34). 
Putting 
T b for temperature of the bath 
T 0 for temperature of surrounding objects 
and assuming 
T,+T,=Z(T b -T 0 )+T„+T 0 .(13#) 
