542 
Trials of Traction-Engines at Wolverhampton. 
li inches, and the length of the stroke 10 inches. This diameter of 7f inches 
gives an area of GO circular inches, thus allowing the Bury standard of just 10 
sucli inches to each horse-power. 
During the trial on the brake this engine was worked at 160 revolutions per 
minute at 115 lbs. pressure of steam, and at 18-horse-])ower, being three 
times its nominal ; aud it consumed 4"42 lbs. of coal per horse-power per hour. 
It evaporated 7'4G lbs. of water per lb. of coal. The average temperature of the 
feed-water was 183°. The oil aud tallow consumed were 1 lb. 15 oz., being 
at the rate of 63 ozs. per actual horse-]lo^^•er per day of 10 hours. 
The indicator diagram, of which Fig. 7 is a coi^y, showed that 20*5 horse- 
Fig. 7. — Indicator Diagram of 3Iessr$. Aveling nd Porter's G-Horse- 
IMiver Locomotive, No. 7002. 
power were developed, equivalent to a consumption of 3'9 lbs. of coal per 
gross indicated horse-power per hour. 
BurrelVs 8-Eorse-2>ower Locom at ive.^ The mxt engine in Group 1 is that of 
Mr. Charles Burrell, No. 3660, 8-horsc-power, price 3101. This is an ent;ine 
of the locomotive type. The fire-box has an area of grate of 3'9 feet. There 
arc thirty-three 25-iu. outside-diameter tubes in the boiler, giving, with the fire- 
box, a total heating surface of 145"33 feet. The flue area through the ferrules 
of the tubes is '63 foot. The cylinder is a single one, of 12 inches length of 
stroke, and 9 inches diameter = 81 circular inches, or 10^- inches 'per horse-power. 
This engine was declared to work at 1 6-horse-powcr, at 120 lbs. pressure, and at 
150 revolutions. The cylinder is fixed upon the fire-box end of the boiler. It 
is cast in one with the steam-chest, on which is mounted the adjustable safety- 
valve; there is a another valve upon the barrel of the boiler. The cylinder is 
steam-jacketed on one side only. 1'he crank-shaft is a forged and not a bent 
shaft, and is su]iported on a saddle-casting bolted on tlie front of the boiler. 
At the right-hand end of the crank-shaft there is a fly band wheel for delivering 
power to a threshing or other machine ; and adjoining that wheel, on its inner 
side, and also at the left-hand end of the crank-shaft, there are sliding pinions 
to be put into gear (when travelling), with spur-wheels carried upon the 
.second-motion shaft. The pinion on the fly-wheel side is for the quick speed, 
and that on the left-hand side is for the slow speed. The second -motion 
shaft carries loose on it at each end two pulleys to take pitched driving-chains. 
These two pulleys are coupled up to the second-motion shaft by clutches, the 
