732 
The Trials of Oil Engines at Cambridge. 
ning it did not show itself quite equal to the Hornsby, and it 
required greater and more skilled attention. 
These two engines were put upon a further trial for three 
hours with Broxbourne oil. The calorific value of this oil was 
certified by Mr. Charles J. Wilson as follows : — 
“ Specific gravity at 60° F. = '8118. 
“ Flash point (Abel test) = 155° F. 
“ Calorific value of Broxbourne oil . — The mean of two concordant ex- 
periments in the compressed oxygen calorimeter gives 1F019 calories per 
gramme, all produced water being condensed. The correction calculated 
from the hydrogen percentage is 742 calories, giving as the heat value 10277 
calories, all products of combustion in the gaseous state at 24° C. 
“ Chaeles J. Wilson." 
This corresponds to a thermal value of 18,500 B.T.U. per lb. 
Broxbourne Oil Trials. 
Engines 
Hornsby 
& Sons, Ltd. 
Crossley 
i Brothers, Ltd. 
Duration, minutes 
180 
180 
Brake power 
Wheel constant per revolution per lb. 
000453a 
•0004775 
Dead load, lb., mean .... 
78 
85 
Spring balance reading, mean 
61 
5 
Nett load on brake, lb 
719 
80 
Devolutions, total during trial 
42,921 
35,972 
„ mean per min. . 
238-5 
199 84 
Brake horse-power 
8-27 
763 
Indicated, power 
Cylinder constant per explosion per lb. . 
002975 
001458 
Mean effective pressure, lbs. per sq. in. . 
30-2 
636 
Explosions per min., mean 
110 
903 
Indicated horse-power .... 
9-9 
8-4 
Mechanical efficiency .... 
•84 
■91 
Oil used 
Lamp oil used, lb. . 
— 
175 x 1 '5 = 2 625 
Engine oil used, lb 
28-5 
15-375 
Total (lamp and engine), lb. . 
285 
18 
Oil per I.H.P. per hr., lb. ... 
•96 
■72 
„ B.H.P. „ „ 
115 
•785 
Jacket water 
Jacket water per min., lb. 
18 6 
8 
Temperature, initial mean, Fahr. . 
63-3° 
64° 
„ final „ 
111 0 
111-7° 
Rise in degrees Fahr 
477 
47-7 
