Set diameter of pulley in inches on C to 3-82 on D, and
over revolutions per minute on D read speed in feet per
minute on 0.
Ex. — Find the speed of a belt driven by a pulley 53in. in diameter
and running at 180 revolutions per minute.
Set 53 on to 3-82 on D, and over 180 on D read 2500ft. per
minute on C.
Ex. — Find the speed of pitch line of a spur wheel 3ft. 6in. in
diameter running at 60 revolutions per minute.
Set 42in. on to 3 '82 on D, and over 60 on D read 660ft. per
minute on C.
Given diameter and number of revolutions per minute of
driving pulley, and the diameter of driven pulley, to find
number of revolutions of the latter.
60 THE SLIDE RULE:

Invert the slide and set diameter of driving pulley on C
to given number of revolutions on D ; then opposite
diameter of driven pulley on C read number of revolu-
tions of driven pulley on T>.
Ex. — Diameter of driving pulley 10ft. ; revolutions per minute 55 ;

diameter of driven pulley 2ft. 9in. Find number of revolutions per

minute of latter.
Set 10 on C to 55 on D, and opposite 2-75 on C read 200 revolu-
tions on D.
VIII. Belts and Kopes.
