356 
PROFESSOR 0. REYNOLDS AND MR. W. H. MOORBT 
thermometer, C, inserted through a cork in the stand-pipe, the part of the stem on 
which readings were taken being exposed to the atmosphere. After being discharged 
from the brake, D, the water entered a flexible rubber pipe, E, bent through an angle 
of 90°, which connected a horizontal nipple at the bottom of the brake with a vertical 
one forming the lower end of a fixed line of copper piping, F. The temperature of 
discharge of the water was indicated by the thermometer, G, which was enclosed in 
a glass tube opening through a stuffing-box into the discharge pipe, the whole 
length of the stem being therefore kept at the temperature of discharge. On 
leaving the copper discharge pipe the water was directed at will by the two-way 
tipping switch, K, either to the left to waste or to the right into the tank, L, 
standing on the platform of the weighing machine, M. 
A series of trials were made with this apparatus, the water being raised through 
varying intervals of temperature between S5° Fahr. and 100° Fahr. For obvious 
reasons the results were not satisfactory, and are therefore not published. 
Experience was gained, however, which helped very materially in the design of the 
final apparatus. 
Common thermometers were used, and calibration errors on the comparatively small 
range of temperature through which the v/ater was raised were of sufficient import¬ 
ance to vitiate all results. Again, the exposure of the stem of the thermometer, C, 
was a weak spot in the apparatus. I was much troubled also with leakage of water 
from the two bushed bearings of the brake. 
In so far as could be judged, the bent rubber pipe, E, was found to be a satisfactory 
connection between the brake and the copper discharge pi^^e, and this has been 
retained in the subsequent apparatus. 
Details op the Constituent Parts of the Final Apparatus. 
Artificial Atmosphere. —(Part I., par. 23.) 
4. To prevent loss of water by evaporation at the centres of the vortices formed 
in the brake, the ports in the vanes of the outer casing were connected through a 
flexible rubber tube some 4 feet long, with an artificial atmosphere formed in a tin 
receiver, the pressure in which was maintained by means of a cycle tyre inflator at 
about 9 inches of mercury, as measured on a U-gauge. The shape of this vessel 
is made clear in the sketch (Part I., fig. 8). The ends were made conical for greater 
strength. The receiver was also provided with an air valve, with which to relieve 
the pressure when too high, and a cock, with which water accidentally lodging inside 
could be drained away. 
