676 
Report on the Trials of Portable 
because they are moderated by the action of the fly-wheel, but 
if it were attempted to obtain an economy equal to that of the 
compound engine by the means under review, the inequalities 
of strain in question would become formidable. 
The Trials. 
The prizes offered were as follows : — 
Class 1. — Portable agricultural engine, self-moving or otherwise, 
on the compound principle, not exceeding eight horse- 
power £200 
Class 2. — Portable agricultural engine, self-moving or otherwise, 
on the simple principle, not exceeding eight horse-power £100 
The brake trials of implements entered in Classes 1 and 2 
will be designed to elucidate relative merit under the following 
head : — 
Construction : — Efficiency — i.e., proportion of actual work 
done to work indicated, economy of fuel, of steam, of lubricant, 
perfection of combustion, price. 
The following engines were entered for trial : — 
No. 3115 — Thomas Cooper (self-moving). 
,, 3124 — Davey, Paxman and Co. 
„ 3113 — E. Foden and Sons (self-moving). 
„ 3116 — Edward Humphries. 
„ 3107 — J. and H. McLaren. 
No. 3125 — Davey, Paxman and Co. 
„ 31 14 — E. Foden and Sons (self-moving). 
„ 3117 — Edward Humphries. 
„ 3108 — J. and H. McLaren. 
„ 3111— The Alnwick Foundry Co. 
„ 147 — Jeffery, Blackstone and Co. 
All these engines, with the exception of Jeffery & Blackstone's, 
a " vertical " of 3 horse-power, were entered as oi eight horse-poiver. 
No restrictions as to the horse-power at which the engines were 
to be worked on the dynamometrical brake were imposed, but 
each exhibitor was invited to declare the horse-power, number 
of revolutions, and pressure of steam at which he proposed to 
run. 
The conditions laid down for regulating the triafls were 
practically the same as those which governed the Cardiff trials, 
the changes being unimportant, and the additions few. Among 
the changes, it was arranged that each engine should run for 
four hours, during which time it might go on calling for coal. 
Then, the coal supply was stopped, and any unused fuel weighed 
back, while the engine continued running until its revolutions 
fell below the declared speed. The additions, on the other 
band, consisted in the collection and analysis of the smoke-box 
Class 1. — 
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Class 2. — 
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