S104

This counter is one of the many inventions of Laroy Starrett (1836-1922). The steel counter has a flat handle on one side and a rotating cylindrical rod on the other. In between is a flat curved case on which a dial is mounted. Pressing the rod against a rotating shaft rotates it and advances the dial. The edge of the dial is divided into 100 equal parts, which are numbered from 10 to 100 by tens. Two different nozzles fit into the far end of the cylinder.

Directions:

This indicator for counting R.P.M. will run at reasonably high speed without trouble. The dial has two rows of figures, each numbered from 0 to 100 (the raised knobs represents 0) so a right to left or left to right motion can be registered. The plain beveled disc, with pressure of fingers, can be quickly turned to any position without slowly turning the spindle. The dial is fixed. The rubber tips, to be slipped over metal tip, permit use against any surface of contact.

Bring the two raised knobs together, press thumb downward on knob of plain beveled disc, to keep the disc from turning while waiting for the watch and then make contact with shaft. When watch shows desired timing point, release thumb pressure and simply count every 100 revolutions as the raised knob passes under the thumb, lightly pressed against it.