qual distance from their axis of motion, which is the axis
of the shaft S.

[Illustration: Fig. 259.]

In Figure 259 we have a case in which the end of a lever acts directly
upon a shoe. Now let it be required to find how much a given motion of
the lever will cause the shoe to slide along the line _x_; the point H
is here found precisely as before, and from it as a centre, the dotted
circle equal in diameter to the small circle at E is drawn from the
perimeter of the dotted circle, a dotted line is carried up and another
is carried up from the face of the shoe. The distance K between these
dotted lines is the amount of motion of the shoe.

In Figure 260 we have the same conditions as in Figure 259, but the
short arm has a roller acting against a larger roller R. The point H is
found as before. The amount of motion of R is the distance of K from J;
hence we may transfer this distance from the centre of R, producing the
point P, from which the new position may be marked by a dotted circle as
shown.

[Illustration: Fig. 260.]

In Figure 261 a link is introduced in place of the roller, and it is
required to find the amount of motion of rod R. The point H is found as
before, and then the length from centre to centre of link L is found,
and with this radius and from H as a centre the arc P is drawn, and
where P intersects the centre line J of R is the new position for the
eye or centre Q of R.

[Illustration: Fig. 261.]

In Figure 262 we have a case of a similar lever actuating a plunger in a
vertical line, it being required to find how much a given amount of
motion of the long arm will actuate the plunger. Suppose the long arm to
move to A, then draw the lines B C and the circle D. Take the radius or
distance F, G, and from E mark on D the arc H. Mark the centre line J of
the rod. Now take the length from E to I of the link, and from H as a
centre mark arc K, and at the intersection of K with J is where the eye
I will be when the long arm has moved to A.

[Illustration: Fig. 262.]

In Figure 263 are two levers upon their axles or shafts S and S'; arm A
is connected by a link to arm B, and arm C is connected direct to a rod
R. It is required to find the position of centre G of the rod eye when D
is in position E, and when it is also in position F. Now the points E
and F are, of course, on an arc struck from the axis S, and it is
obvious that in whatever position the centre H may be it will be
somewhere on the arc