214 
PROFESSOR 0. REYNOLDS ON THE THEORY OF LUBRICATION 
33a. The maximum Load the Journal will carry at any Speed. 
It has already been pointed, out that the carrying power of the journal is at its 
greatest when c is between '5 and ’6. If, therefore, taking the load constant, c passes 
through a minimum value as the velocity increases with a constant load, then the load 
which brings c to a constant value will be a maximum for some particular velocity, 
and if the particular value of c be that at which the carrying power is greatest, the 
carrying power will be greatest at that particular speed. 
The question whether, according to the theory, journals have a maximum carrying 
power at any particular speed turns on whether 
dL 
(c being constant) 
is zero for any value of U. 
This admits of an answer if the values for y. , a, T. r , and equations (119) and (120) 
hold, for when c is constant 
/ 
KfU’ K 2 U 
substituting it appears that when c is constant 
, and A are constant, whence differentiating and 
cVL 
dL 
. B 
A + tJ + | 
(AE-(3E + C)g 
)t-AE 2 T 2 
. B | 
A + u + 1 
|(3E + C)A + (E + C)|jJ 
-T + AE(E + C)T 2 
. (123b) 
where U is to be taken positive, and T increases as U increases. This shows that 
”, for a constant value of c, changes sign for some value of U if T continues to 
increase with U. 
Hence, according to the theory, the values of L, which make c constant as U 
increases, approach a maximum value as U increases, and since this value, when c is 
about T), represents the carrying power of the journal, this approaches a maximum as 
IT increases. 
Section IX.— Application of the Equations to Mr. Tower’s Experiments. 
34. References to Mr. Tower’s Reports. 
From the experiments described in Mr. Tower’s Reports I. and II., in the Minutes 
of the Institution of Mechanical Engineers, 1884, the journal had a diameter of 
4 inches, and the chord of the arc covered by the brass was 3'92 inches, the length of 
the brass being 6 inches. 
The loads on the brass in lbs., divided by 24, are called the nominal load per 
square inch. 
