1022

THEORY AND PRACTICE OF ENGINEERING.

Book II.

Fig.1558.

RAILWAY CARRIAGE .

upwards, and is on the inside of the frame, to which it is securely bolted. The dotted linesrepresent the checks of the chair, within which the guides slide up and down. These arecarefully fixed, to prevent any twisting or oscillation, to which the framework would be

Fig. 1559.

FLAN 01' CARRIAGE.

subjected. These trucks on a railway 4 feet 8 inches in width have a superficial area ofplatform equal to 75 square feet, and generally carry about 4 tons weight.

The second class passengers’ carriages have the same kindof frame, on which iron uprights support a curved top ;they are partly inclosed, and the seats arc arranged betweenthe divisions. These carriages have sometimes a semicir-cular bearing on the axle by means of a chair, which is ———bolted to the framing of the carriage by two bolts, theunder side of which embraces the lev^r half of the axles

diameter, and is bolted to the chair above. Oil is poured _

upon the axle through a cup and small tubular passage which is

sometimes made suf-ficiently capacious tocontain a cotton wickwhich drops the oilupon the axle as itis required.

In many carriagesthe bearing is on theoutside of the wheels,the end of the axlebeing diminished gra-dually towards its ter-mination, where it isagain increased toprevent its sliding.The chair is an ironbox cast in two, se-

Fig. 1560. axi.es of carriages, etc. Fig. 1561.