156 The Trials of Suction Gas Plants at Derby , 1906. 
producers and engines would, in many cases, be placed in the 
hands of agricultural labourers, to whom very little discretion 
could be given in mechanical matters ; and therefore means of 
adjustment intended to obtain some small economical advan- 
tage would not be of the same value as when in the hands 
of a skilled attendant. 
The size of plant fixed upon for trial was from 15 to 
20 B.H.P., this size being suitable for threshing and other 
agricultural purposes. 
Discussion of the Regulations. 
The principal regulations issued by the Society, under 
which the trials were carried out, were as follows : — 
1. The plant to consist of gas generating plant and engine, complete, 
of 15 to 20 B.H.P. as a maximum. 
2. Each engine must be fitted with a rope or web brake on the flywheel, 
water trough in wheel for cooling, indicator cock and gear, revolution counter 
and explosion counter, to be approved by the Society’s Consulting Engineer. 
Water will be found by the Society. 
3. One attendant must be in constant charge of each plant to give any 
information which the Judges may require. Any attention actually given 
by him to the working of the plant will' be noted. 
4. Each exhibitor will declare at what B.H.P. he intends to run his 
engine for the full load trial, and no variation therefrom beyond 5 per cent, 
more or less will be allowed. • 
5. Full load, half load, and light or no load trials will be made with 
uniform selected anthracite coal provided by the Society. A subsequent full 
load trial will be made with coke as fuel. Each plant will be started from 
cold on the full load trial. The first full load trial will be commenced with 
the gas generators empty. 
6. A given quantity of coal will be weighed out to each competitor, the 
time of lighting up will be noted, and so soon as sufficient gas has been 
generated and the engine is running at full power the time will be taken. 
This time will be recorded as the commencement of the run, so far as fuel 
consumption is concerned. 
7. The engines will run for nine hours under constant load, after which 
they will be shut down for the night, and will resume running on the following 
day. At the conclusion of the trials the fires will be drawn, and any 
unconsumed coal will be weighed back and credited for what it may be worth. 
8. The half load trials will be conducted on precisely the same lines as 
the full load trials, with the exception that they will be of shorter duration. 
9. The light or no load trial will be of two hours’ duration. No coal 
consumption will be recorded for this trial. No working of the fan by hand 
will be permitted during the half load and light or no load trials. 
10. On the completion of the above trials, one full load trial of nine 
hours’ duration will be made, using coke as fuel. 
1 1 . The points to which special attention will be directed are : — 
(1.) Attendance necessary. 
(2.) General design — including facility of cleaning — and space 
occupied. 
(3.) Regularity of working. 
(4.) Fuel consumption. Water consumption. 
(5.) Price. 
(6.) Relative proportions of gas producer and engine. 
(7.) Volume swept by piston relative to B.H.P. 
