Trials of Portable Steam- Engines at Cardiff. 
79 
The crank-shaft is carried in two cast-iron brackets, bolted to the boiler 
over the fire-box. The brasses in those brackets have, on the fl\'-\vhecl side, a 
vertical adjustment, and on the opposite side they are in three pieces with a 
horizontal wedge adjustment. The crank-shaft is of the " bent" kind, and is 
of wrought iron. 
The guide-bar is a single one, slotted down the middle, attached to the 
cylinder stuffing-box at one end, and to a bracket fast to the boiler at the 
other. Tiirougii the slot is an arm, which connects the cross-head to a guide- 
block bearing on the under side of the guide-bar. This guide-block has a lug 
jx)inting downwards, which gives motion to the feed-pump plunger. The 
pump is easily inspected, it is provided with a flexible suction-pipe to dip into 
the feed-water pail. The pipe from the rising clack-lxix is carried alongside 
the boiler to near the smoke-box end, where it enters the boiler through a 
check-valve. There are no means of heating the feed. 
The bearing-wheels are of wood, Mith iron tyres. The hind-wheels are 
fitted to a wrought axle, bent to pass beneath the fire-box, to which it is attached 
by brackets. The fore-wheels are fitted to an axle secured to a wood bed. 
There is a flanged iron bracket, riveted to the under side of the boiler at the 
smoke-box end, which carries a perch-pin ; the bottom of this pin is stayed to 
the lire-box, and there are two chains to regulate the amount of locking. 
This engine, upon trial, ran for 2 h. 30 m. actual time, and for 2 h. 25 in. 6 
mechanical time, giving a consumption of 5*78 lbs. of coal per brake horse- 
jx)wer per hour. The indicator diagram shows that 14 '27 gross indicated 
horse-power were developed, making a consumption for each such horse- 
power of 4 ■ 87 lbs. of coal per hour. 
The feed water was cold when pumped in, the quantity evaporated was equal 
to 1506 lbs. at 212°, equivalent to 8*97 lbs. at 212° per lb. of coal. 
On the trial of the engine to ascertain the power of the governor, it was 
found that the engine was under fair control. 
The last engine which was tried was that of Messrs.^ Ashby, 
Jeffreys, and Luke, of Stamford (No. 4004). Price 230/. 
The cylinder is 9j inches diameter, by 1 foot 2 inches stroke. The total 
heating surface is 204 "5 feet. The total fire-grate is 5 '5 feet, but this was re- 
duced, by fire-brick, during the trial to an area of two square feet, in two 
sections of 1 foot eacli* 
The Exhibitors determined to run at 120 revolutions jrer minute, at 8-horse- 
power, and at 80 lbs. pressure of steam. 
The cylinder is bolted upon the fire-box ; it is jacketed all round its 
circumference, and at the ends. The crank-shaft is of the " bent " tyi)e, and 
is made of wrought iron ; it is carried in bearings supported by two horns on 
a single broad casting, bolted to the top of the boiler, at the smoke-box end. 
The bearings have adjustment for endway wear. On the back of the main 
slide-valve, which is composed of two short slides coupled by bolts, there is 
an expansion slide of similar construction. 
The governor is of the ordinary kind, working an ordinary throttle-valve. 
The guide-bar is a single one of wrought iron. The guide-block is of cast 
iron, working upon the bar, and flanged round to grasp its under side at 
the edges. 
The exhaust on leaving the cylinder passes through two pipes, which 
embrace the barrel of the boiler as far as the under side, where these pipes 
turn longitudinally, and enter into two 22 tubes, which convey the exhaust 
to the blast-pipe in the smoke-box. Inside these tubes are two Ij-inch pijies 
conveying the feed on its way from the feed-pump to the boiler. The pump 
is worked by an eccentric on the crank-shaft. The pump-valvos work in 
conical seats, and have conical faces, and these cones are prolonged below the 
