AND ITS APPLICATION TO MR. B. TOWER’S EXPERIMENTS. 
229 
This is so far in accordance with the conclusions of Art. (33a), for substituting the 
values of A B C E, as determined Art. (37), it appears by equation (123b) that the maxi¬ 
mum would not be reached until T m , the rise of temperature due to friction, reached 
72° Fahr., which, seeing that at a velocity of 450 revolutions T m is less than 17°, implies 
that the maximum carrying power would not be reached until the speed was 1500 or 
2000 revolutions; notwithstanding yjy c constant is very small at 450 revolutions. 
This is with the rise of temperature due to legitimate friction with perfect lubrica¬ 
tion. But if, owing to inequalities of the surfaces, there is excessive friction without 
corresponding carrying power, i.e., if n, the effect of necking, is as large as 3 or 4, 
which it is with new brasses, then the maximum carrying power might be reached at 
comparatively small velocities ; thus suppose T=13 when N=100 U = 21, Equation 
(123b) gives 
clL 
d\J 
= 0 , 
or the maximum carrying power would be reached ; all which seems to be in strict 
accordance with experience, particularly with new brasses. 
42. Application of the Equations to Mr. Tower’s Experiments with Brass No. 2 to 
determine the Oil Pressure round the Journal. 
The approximate equation (74) is available to determine the pressure at any part 
of the journal, i.e., for any value of 6 so long as c is small, but these approximations 
fail for much smaller values of c than for others, for this reason, together with the fact 
that the only case in which the pressure has been measured c is large, the pressures 
have only been calculated for c=‘5, in which the approximations have been carried to 
the extreme extent. 
These are obtained directly from equation (107), and the pressures divided by Kp? 
are given in Table II., Section VI. 
The results of Mr. Tower’s experiments with brass No. 2 are given in Table XII., 
Art. 34. 
Had the friction been recorded in the experiments in which Mr. Tower measured 
the pressures with brass No. 2 as with brass No. 1, the values of c might have been 
obtained as in the case of brass No. 1. But as this was not done the value of c for 
these experiments with brass No. 2 could only be inferred from the agreement of the 
relative oil pressures measured in different parts of the journal, those calculated for 
the same parts with a particular value of c. This was a matter of trial, and as it was 
found that the agreement was very close when 
c= ‘5, 
further attempts were not made. 
