Report on the Trials of Implements at Oxford. 453 
fire-bars -| inches thick, by 1-| deep, and from to i inch spaces. Size of 
fire 1 ft. 5 inches ; 2 feet 9 inches diameter outside the shell ; 6 feet higli. 
Packing of piston, with gauge, bottom ring. Boiler covered with one thick- 
ness of felt, and 1 j wood and sheet iron. Cylinder covered in the same man- 
ner, but not steam-jacketed ; weight about 33 cwts. Standing space, 4 feet 
3J inches by 3 feet 5 inch. The flj'-wheel projects 6 inches in width and 
1 ft. 4 inches in extra length. Stoke-hole at opposite end ; two glass gauges ; 
no gauge-cocks; blow-off cock. Chimney about G feet above toji of dome. 
Engine tolerably steady in working. 
No. 5. Ashby and Jefl'rey. 478. — Upright boiler with upright engine 
attached to it. Cylinder at top ; 6f inch double cylinder, 10-inch stroke, 150 
revolutions per minute. Boiler has two horizontal tube-plates, provided with 
37 tubes (If inches outside, and 1^^ inches outside), 5 feet 4 inches long, being 
4 feet in water and 1 ft. 4 inches in steam. The lower tube-plates would pro- 
bably require frequent cleaning, as it is commonly found that a horizontal 
tube-plate over the fire cannot get well supplied with water, especially if the 
latter is bad. Fire-box, 22^ inches diameter. In centre of fire-bars there is a 
raised boss of clay, enclosed within cast-iron ring, slightly conical. This boss 
is 11£ inches diameter at top. The radial rings of the bars outside of this 
boss are 5 inches and 3-|- inches. The bars are f to -pgths in thickness, having 
spaces between f tapering to \ of an inch. The governor is attached to the 
side of tiie cylinder, driven by a strap and gear. There is a working slide and 
an expansion slide, driven by a separate eccentric, capable of adjustment when 
standing, by a bolt and nut and slot. The feed-pump is drawn by a separate 
eccentric. The steam is cut off at about 3 inches, but may be varied consider- 
ablj^ Guide to piston-rod is a single guide-bar of steel, having ample sur- 
faces, capable of adjustment by packing behind the bars, contained within a 
sliding plate block. The crank end of connecting-rod has amj^le surfaces pro- 
vided with good bars. There is no drum on crank-shaft, but a good fly-wheel, 
with proper balance-weight. The feed- water heater is formed in the foun- 
dation-bed, and is heated entirely from the ashpan. The feed is regulated by 
a cock in the suction. The ashpan has a damper, and the boiler a blow-off 
cock. The boiler is enclosed in IJ inch of non-conducting composition (lime 
material), and sheet-iron casing outside. Two gauge-cocks and glass gauge. 
A proper gauge and safety valve, like all the other engines tried ; 4 feet chim- 
ney ; base, 2 feet 9^ inches square. Fly-wheel projects on the side 5J inches, 
and at end 2 feet 5 inches. The boiler has proper mudliole doors. Boiler, 
2 feet 4^ inches diameter; height 5 feet 11 inches. Five thicknesses of pack- 
ing. The engine ran remarkably steadily, no doubt owing to the balance- 
weight being correctly adjusted. The pump may have to lift the water 
18 inches ; the water, therefore, cannot be allowed to become very hot. Total 
weight about 27 cwts. 
No. 8. Brown and May. Horizontal tubular boiler ; 21 tubes, 2i inches 
diameter inside, made of No. 10. Bii-mingham wire-gauge ; 5 feet 7 inches long. 
Horizontal engine with cylinder placed on top of fire-box, l-f-^ inches dia- 
meter, 12 inches stroke, 120 revolutions per minute. Steam cut off at about 
2J inches ; can be varied greatlj', as there is separate expansion slide and 
eccentric, capable of adjustment, when the engine is standing, by bolt and nut 
and slot. The governor stands on the boiler, is driven by a strap and bevilled 
wheels. The cylinder is steam-jacketed and lagged. The valve-box is also 
lagged. The eduction steam passes the whole length of the boiler, through a 
feed-water heater, provided with an air vessel on the top to prevent its being 
affected by frost. The pump is worked by a separate eccentric, which pumps 
the cold water through the feed-water heater into the boiler, so that it is 
quite capable of drawing the water from the level of the ground, or even from 
a sliallow well. The pump always works full. The feed is regulated by 
