(1) by driving the governor faster or slower relatively to the speed of
the crank shaft;
(2) by altering the position of W on D;
(3) by altering the compression of the spring by shifting F;
(4) by a combination of two or more of the above.
Generally speaking, (3) is to be preferred, as the simplest.
The belt may be made out of a bootlace or fairly stout circular
elastic. In either case the ends should be chamfered off to form a
smooth joint, which may be wrapped externally with thread.