n Fig. 58 the lacing should commence at the center hole (A) of one belt
end and lace outwardly, terminating at the hole (B) in the center of the
other belt end, as shown in Fig. 58.

In Fig. 59 the lacing commences at A, and terminates at the hole (B) at
the edge. This will be ample for all but the widest belts.

Fig. 60 is adapted for a narrow belt. The lacing commences at one margin
hole (A), and terminates at the other margin hole (Z).

Fig. 61 shows the outside of the belt.

Fig. 62. GEARS.--This is something every boy ought to know about. Fig.
62 shows a pair of intermeshing bevel gears. This is the correct term
for a pair when both are of the same diameter.

[Illustration: _Inside Fig. 58. Belt Lacing_
_Outside Fig. 58. Belt Lacing_
_Fig. 59. Belt Lacing_
_Fig. 60. Belt Lacing_
_Fig. 61. Belt Lacing_]

MITER GEARS.--In Fig. 63 we have a pair of miter gears, one being larger
than the other. Remember this distinction.

Fig. 64. CROWN WHEEL.--This is a simple manner of transmitting motion
from one shaft to another, when the shafts are at right angles, or
nearly so, without using bevel or miter gears.

Fig. 65. GROOVED FRICTION GEARING.--Two grooved pulleys, which fit each
other accurately, will transmit power without losing too much by
friction. The deeper the grooves the greater is the loss by friction.

Fig. 66. A VALVE WHICH CLOSES BY THE WATER PRESSURE.--The bibb has
therein a movable valve on a horizontal stem, the valve being on the
inside of the seat. The stem of the handle has at its lower end a crank
bend, which engages with the outer end of the valve stem. When the
handle is turned in either direction the valve is unseated. On releasing
the handle the pressure of the water against the valve seats it.

Fig. 67. CONE PULLEYS.--Two cone pulleys of equal size and taper provide
a means whereby a change in speed can be transmitted from one shaft to
another by merely moving the belt to and fro. The slightest change is
available by this means.

Fig. 68. UNIVERSAL JOINT.--A wheel, with four projecting pins, is placed
between the U-shaped yokes on the ends of the approaching shafts. The
pins serve as the pivots for the angles formed by the two shafts.

Fig. 69. TRAMMEL FOR MAKING AN ELLIPSE.--This is a tool easily made,
which will be of great service in the shop. In a disc (A), preferably
made of brass, are two channels (B) at right angles to each other. The
grooves are undercut, so that the blocks