460
STEPHENSON’S PATENT
across the ends, serving to support the whole engine, which is firmly fixed to it. It is
made of good tough ash plank, the side pieces N' N' are three inches thick and seven
inches deep, and covered on both sides with sound wrought iron plates, a quarter
of an inch thick, fixed on by a number of iron bolts; the best plates are termed
Low Moor plates. The side pieces are morticed into the end pieces, O' P', of the
frame; that in front of the engine, O', being five inches thick, and thirteen deep ;
angle pieces of iron are bolted on to strengthen the corners inside and out. The
outside length of the frame is 17 feet, and the width 6 feet 4 inches. The boiler,
fire-box, and smoke-box, are fixed to the side frames, N'N', by strong wrought
iron stays, u v, four inches and a half wide and half an inch thick. The stays,
u'u\ for the smoke-box and fire-box, consist of a horizontal piece, (see Plate
XCII.,) bent downwards at right angles at the inner end, and riveted to the
side plate of the fire-box or smoke-box, and resting at the other end upon the side
frame; the other inclined piece is welded on to it at the outer end, the two being-
bolted down to the frame, and it is riveted like the other piece at the upper end to
the plate ; the inner ends of both that are riveted to the fire-box and smoke-box
are made T shaped and twelve inches wide. The stays, v v, for the boiler are made
and fixed in a similar manner; they are longer, as shewn by the dotted lines in fig. 4,
(Plate XCII.,) in order to reach the boiler, and have a ring of the same sized iron
inserted in them, touching the horizontal and inclined pieces of the stays and the
sides of the boiler, and riveted to each of them.
Q' Q' Q' are wrought iron plates, seven-sixteenths of an inch thick, bolted on to each
side of the frame at the axles, and called the axle guides; serving to hold steadily the
boxes that contain the brasses bearing on the axles, and to guide them when they
slide up and down from the play of the springs. A piece 4^ inches wide is cut out
in the middle of each for the axle box to slide in. These axle guides have to resist
all the strain of the wheels, and those of the driving wheels have to bear the whole
force of the engine, which is moved along by the axle of the wheels. They are there
fore strengthened by inch rods, w' iv\ fixed between each of them, with sockets
across their ends, fitting between the two axle guide plates, and fixed to them by
bolts passed through both ; the extreme rods are fixed to the end frames of the
engine, as in Plates LXXXIX. and XC.; the axle guides for the small wheels have
also bolts fixed through the bottom.
R' R' R' are the axle boxes in which the axles turn; they are all alike, and are
shewn to three times the scale, or 2^ inches to a foot, in figs. 38, 39, and 40.
Fig. 38 is a section along the centre of one of them ; fig. 39 is a cross section; and
fig. 40, a plan of the top. A A is a cast iron box, open at the bottom and
the inner side, and 4^ inches wide, so as to fit into the opening in the axle guides.
A hollow, B B, is cast in the top of the box A A, for the purpose of holding oil to