30 TECHNOLOGY. 
the most convenient arrangemert is there thought to be a division of the 
car into three or more separate apartments, holding eight to ten persons 
each, as seen in pl. 5, jigs. 24 and 25. In the United States, however, most 
of the cars at the present time have but one apartment, the seats being 
arranged transversely two upon each side of a centre passage. In Europe 
the first-class cars are fitted up with great elegance. Jig. 29 shows the 
interior of the Duke of Brunswick’s car upon the Brunswick railroad, and 
jig. 30 Queen Victoria’s car upon the London and Dover railroad. 
For the transport of merchandise which must be protected from the 
weather long tight cars closed on every side are used, as seen in jigs. 27 
and 28. For the transport of sand and other materials not injured by the 
weather, cars are used with low sides and without roof; figs. 22 and 23 
show a car for the transport of wood. For the transport of animals cars 
formed of slats or grating are used ; they are also furnished with rings to 
which to secure the animals. 
The car trucks are of the same size in all passenger cars. The height of 
the wheels is always 3 ft., and the carriage frame rests upon springs which 
are secured to the journal-boxes, as shown in pl. 5, figs. 22-24 and 27. A 
species of spring much preferred at the present time is seen in jig. 18; this 
spring gives a particularly easy motion to the cars. The spring d consists 
of a single piece of steel and is secured to the main frame f at g by means 
of a link joint, and to the axle-box at c; dd are chains which unite the 
ends of the springs and secure them to the axle-box. At first it was pre- 
sumed that these springs would be easily broken, and to guard against this, 
the additional springs, e, were applied. 
Pi. 5, jig. 26, shows a portion of the frame of a passenger car as some- 
times constructed ; it consists of the timbers, /f and g, strengthened longi- 
tudinally by the centre beam dd, and also by the diagonal braces ¢,; the 
steps 72, for the accommodation of passengers, are secured to the frame. 
To neutralize the effect of the concussions of one car against the other while 
in motion the so-called buffers are applied to each end of the carriage 
frame: these are leather cushions upon the ends of rods, 6, which rods are 
attached to springs, a, beneath the body of the carriage. The buffers 
receive the shocks and prevent them from annoying the passengers. In 
freight wagons the springs are dispensed with, and only the leather cushions 
are used. In eight-wheel cars it is necessary that the wheels be permitted 
to accommodate themselves to the curves of the track, to a degree which 
would be impossible were the axles secured rigidly to the car-frame. Without 
some provision of this kind great friction and a speedy destruction of the rails 
and wheels would result. To effect this flexibility the wheels are secured in 
small frames called trucks, upon the centre of which the main car-frame is 
permitted to pivot, as seen in pl. 5, fig. 27; jigs. 17 a and 17 6 show an 
arrangement for accomplishing this purpose, contrived by Ross Winans, 
an American engineer, at the time of the introduction of eight-wheeled 
cars; fig. 17 @ is a bolster secured beneath the main frame of the car with 
the ring-bolt d projecting downwards, and into a cavity in a corresponding 
bolster (fig. 176), which is secured to the centre of the wheel-truck. This 
610 
