526 Report on the Trials of Implements at Oxford. 
account of the action of tlic spring interfering with the driving-gear. The 
manner in which this difficulty lias hcen surmounted will be understood by 
reference to the following drawing, which is a section through 
the hind axle. 
aa is a large spring resting on the hind axle, h, to which 
the boiler is firmly suspended by a strong link, c. The 
brackets, dd, are bolted to the boiler, and take hold of the 
axle by means of slotted openings, through which the axle 
passes; this allows of an up and downward motion of the 
axle, according to the pressure placed on the spring a. 
The brackets have also a cylindrical portion surrounding 
the square slots, through which the axle, h, passes {vide 
sketch. Fig. 19). This is turned, and forms the centre pin or stud, round 
which the two last spur-wheels of the road- motion gear are turning. 
The road-wheels, which are 
Fig. 20. — Section of the front axle of Fowler. 
Traction Engine. 
no. 
loose on the hind axles, are con- 
nected with these spur-wheels by 
means of pins, ee, which can be 
taken out on one or the other side 
if the engine is required to turn 
very sharp comers. 
It is thus evident that the hind 
axle will move up and down in 
the slotted brackets according to 
the play and the vibrations of the 
spring, whilst the driving spur- 
wheels will continue to gear into 
the corresponding pinion undis- 
turbed by the action of the spring. 
This is a very ingenious arrange- 
ment, which appeared to the 
Judges to answer perfectly. 
The front axle rests on a spiral 
spring, which is placed in the cylin- 
drical portion of the cast-iron 
bracket supporting the smoke-box 
end of the boiler, as shown in the 
following section. 
The ability for rapid change 
of direction is not so great as in 
either Thomson's or Aveling's inventions. The engine is of 8 horse-power 
nominal, and costs 400Z. 
Although the Miscellaneous Judges omitted to notice Aveling and Porter's 
nominal 5-horse power Traction-Engine, Article No. 6653, which was so 
usefully employed as the power in the horse-gear trials, we have been requested 
to explain that this was entirely an oversight, which was only discovered when 
the awards had been completed, and therefore not in any way to be considered 
as disparaging to this engine, of which they entertain a very favourable opinion. 
Without the test of actual comparison and experiment it would be unwise to 
pronounce an opinion as to the relative merits of the different traction-engines 
which appeared at Oxford, more especially since this class will come into compe- 
tition next year. The engine before us, of which a side-view is given in fig. 2, 
p. 462, is noticeable for the small space it occupies, for its lightness, and for the 
actual power of which it is capable, consequent on great strength. Mr. Aveling 
worked the engine with a break on the fly-wheel, and showed a power of 10 
horses, with a pressure of from 55 to 60 lbs. per square inch. Hence it is quite 
reasonable to expect a result equal to 15-horse power, under a pressure of about 
