458 Report on the Trials of Implements at Oxford. 
is admitted and exhausted alternately from each end of the cylinder. This 
arrangement is iti lieu of the slide-valve' or other apparatus lor admitting and 
exhausting steam. At the cylinder end of the fly-wheel shaft, the end opposite 
to the plug, there is a fixed pin placed at 5 inches above the common centre of 
the cylinder and fly-wheel shaft. Upon this pin revolves a block which is 
contained within a slide formed in a cast-iron frame, which frame embraces 
the cylinder and is attached to the two ends of the piston-rod, which issues 
from both ends of the cylinder. By this arrangement it will, on consider- 
ation, be seen that when the steam is admitted to press upon the piston, 
it tends to drive the frame endways, and by this means a side pressure is put 
on which causes the revolution of the entire cylinder with the cast frame 
within which the cylinder is placed. To enable this revolution to take place, 
however, it is obvious that there must be a sliding motion between the 
cylinder and the frame before referred to. Thus, there are two sliding motions 
— one in the direction of the line of the cylinder, and another at right angles 
to that direction. It is obvious that this is a construction which must give 
very large friction — friction of the nature that occurs in those engines known 
as " dog-crank " engines, the term applied by mechanics to the slotted piston- 
rod commonly used in small engines where there is not any connecting rod. 
But the friction here is far worse than that of any ordinary dog-crank, for 
that friction, at all events, is put on in the centre line of the machine, 
whereas here it is put on at one side. As might have been expected, the 
results of the endeavours to work this engine were most unfavourable. Mr. 
Ellis elected to run at 125 revolutions. He called his engine 8-horse-power. 
The computed weight upon the break was 230 lbs. The fly-wheel of the 
engine was very small, and the break-revolutions consequently slow ; but the 
engine was never able to lift this weight at 125 revolutions, nor indeed at 
any greater number of revolutions than 42. The load was reduced weight by 
weight to endeavour to see what the engine would lift when at the speed of 
125 ; but it was found to be far below this speed even when only 36 lbs. 
weight remained. We then directed the strap to be thrown off and the 
engine to be run as fast as it would go. This turned out to be 126 revo- 
lutions, per minute, or one revolution more than it was intended to have 
kept up when the full load was on. A result so absurd that no further trial 
of the engine was attempted. We almost regret that we did not try the 
■consumption of coal at the 42 revolutions, as we believe, from the immense 
amount of steam that went through tlie engine, it would have proved very 
large. Irrespective of fuel consumed, the utmost duty of this machine was 
one-third of its nominal power. It has been thought well to go at some length 
into a description of this engine, as it may probably cause persons of an in- 
ventive disposition, but without jiractical experience, to pause before they 
embark money in carrying out crude ideas. 
No. 2. E. R. and F. Turner, 4831. — This was a horizontal engine on a framed 
cast-iron bed-jjlate, planed all over, having a wrought crank shaft proceeding out 
from one side of the engine ; that is to say, not a shaft having bearings on both 
sides. In lieu of a crank there was a cast-iron disc into which the crank-pin was 
inserted. The engine was jacketed with steam both round the cylinder and at 
the ends. There was an expansion-slide at the back of the main slide, and the 
throw of this expansion-slide was regulated by the action of the governor, 
raising or lowering the slide-block in a link placed very near to the expansion 
eccentric and worked by it. The governor was driven entirely by gearing, and 
there was no throttle-valve or other mode of regulation than the varying of 
the expansion above mentioned. The feed-f)ump was worked off a third, 
eccentric placed outside the governor. The main eccentric was situate in the 
middle of the plummer-block, which was separated into two portions to admit 
of the eccentric thus occupying such position. On trial this engine ran for 
