368 
PROFESSOR O. REYNOLDS AND MR. W. H. MOORBT 
V. At intervals of two minutes thirty observations were then taken of the 
temperatures of supply and discharge of the water to and from the brake, and also 
at each of these intervals a note was made of the reading of the speed gauo-e. 
At intervals of four minutes fifteen observations were made of a thermometer 
registering the temperature of the room. Also at intervals of eight minutes readings 
were taken of the two thermometers in the stuffinof-box and on the main bearino’. 
VI. When sixty-two minutes had elapsed the counter was freed from the shaft, at 
the same time the water being again diverted to waste. 
The drain pipes from the stuffing-box and cock were removed from their respective 
bottles. 
Headings were taken of the speed indicator and of the temperature of discharge. 
YTI. Fresh observations were made of— 
{a) The reading of the revolution counter. 
[h) The weight of the tank and water received during the trial, to W’hich 
had been added the Avater caught from the refifulatinef cock. 
4 record was also made of— 
(c) The weight of Avater Avhich had been caught from the stuffing-box. 
18. These observations Avere afteiuvards reduced as folloAvs :— 
Let T^ = mean temperature of Avater supplied to the brake. 
Tg = ,, ,, discharged by the brake. 
= Aveight of tank and contents before the trial. 
Wj = ,, ,, after the trial, 
w = weight of water caught from the stuffing-box. 
t = rise of reading of the thermometer in the discharge pipe during the trial. 
Ts = mean temperature of the stuffing-box cover. 
Tb = ,, ,, loAver brass of the main bearing. 
Ta = „ „ air. 
Nj = reading of revolution counter before the trial. 
Ng = ,, ,, after the trial. 
M = moment in ft.-lbs. carried by the brake. 
Therefore Ave haAm for the total heat generated 
H = (W. - Wi) (To » T,) + (Ts - Tb) C + (T^ - T,)R. 
The determination of the cpiantity X and of the constants C and R, representing 
the losses by conduction and radiation Avill be dealt Avith later (pars. 30, 43 and 45). 
Also the total Avork done 
U = 277 (Ng — Nj) (M + m), 
Avhere m = error in balance of the brake. This error Avill be dealt with subsequently 
(par. 29). 
