452 Report on tlie Trials of Implements at Oxford. 
minute. This boiler lias Field's patent tubes, 36 in number, and 2 feet 3 inches 
long. The tubes have smaller circulating ]iipes inside them. The steam is 
cut off by a slide worked by an eccentric capable of adjustment by means of the 
governor whilst running. The slide was set to cut off at about one-third of 
the stroke, and the governor allowed it to vary somewhat above and below 
this degree of expansion. This arrangement tended to uniform speed, even 
■with a variation of from 50 to 331bs. pressure per square inch. The governor is 
horizontal on the crank-shaft itself, and is provided with a large spiral spring 
around the shaft, to resist the centrifugal force of the governor-balls. It is a 
powerful governor, in order that it may be able to move the wedges which, 
regulate the eccentric, so as to vary the expansion. We do not, however, con- 
sider there is any substantial advantage in this arrangement over an ordinary 
■working slide and an expansion capable of adjustment in its eccentric before 
starting. The cast-iron brackets for carrying the crank-shaft plummer-blocks 
are fastened to the boiler. The heavy fly-wheel is jsrovided with a balance- 
weight, and runs very steadily. No drum is attached, unless ordered. The 
engine stands in a space of 4 feet 1 inch by 3 feet 11 inches, and was remarkably 
steady in running, although merely p)laced on loose wooden packing (four 
thicknesses). The fly-wheel projects 5 inches in width, and 2 feet 5 inch be- 
yond the end. The wheel is 6 inches wide. The cylinder is steam-jacketed, 
and the boiler covered with 1 inch lagging. The feed water has an adjustment, 
so that the pump always draws full. The pump may have to lift the water 
18 inches. When the water is not required in the boiler, it is allowed to pass 
back by the cock being partially opened. There are four guide-bars to the i)iston- 
rod. The boiler is provided with proper mudhole doors, and gauges for showing 
the level of the water in the feed-water heater. The bed-plate being hollow, 
forms the feed-water heating tank, wiih a division, so that the centre plate 
forms the ashpan. This is all but universal with this character of upright 
toilers. There are close-fitting ashpit dampers, two guide surfaces, glass gauge, 
gauge-cocks, small blow-off cock, and other proper fittings. The steel crank- 
shaft is bent. The stoke-hole is at the opposite end to the fly-wheel. The 
fire-bars are f of an inch thick, with -^^ spaces. The diameter of the fire is 17 
inches, with bricks round the inside of the fire-box. There is a 3-iuch water- 
space around the fire-box. The height of the steam-space is 26 inches. The 
height outside the casing is 7 feet 6 inches ; the diameter 3 feet 2^ inches. 
The height of the chimney above the top of the boiler is 8 feet — 12 if required. 
The total weight is said to be about 53 cwts. The packing is one wood inside, 
■R'ith two outside. 
No. 3. Eiches and Watts. 7136. — Vertical boiler with upright engine, on 
cast-iron independent standards, fixed on the same cast-iron bed which bears 
the boiler; 3Hnch cylinder; 10-inch stroke; 150 revolutions per minute; 
steam cut off at 3i. The fire-box has a horizontal ring tube-plate, cupped 
down 1 ft. 8i in. in the centre, from which a circle of 14 vertical tubes 
extends to a flat tube plate on the top of the boiler. Thus the upper parts of 
the tubes pass through the steam-space, and, in addition to this superheating, 
the steam-pipe coils round the inside of the chimney-dome at the top of the 
Loiler. The fire-box itself is conical. Small governor at upper part of boiler, 
driven by strap and bevilled gear, to act upon throttle-valve. Working slide 
and exf)ansion eccentric. Eccentric capable of being set when the engine is 
standing, by bolt and nut and slot. Feed-pump driven off the same eccentric. 
Guide surfaces, in place of separate bars, on the insides of the standards, with 
ample surfaces, well got up. Adjustment on the block by very thin packing. 
Wrought-iron crank-shaft with bearings on each side of crank, and one at the 
fly-wheel. Balance-weight on light fly-wheel, and drum. Feed-water heater 
and feed-pump arrangement. Pump may have to lift water 8 inches. Two 
gauges to heating tank, which is within the bed-plate ; ashpit. Wrought-iron 
