The drill is automatic in its action, and the speed can be regulated by friction gearing.
"Scientific American Supplement, No. 520, December 19, 1885" by Various
The gearing throughout is of friction pulleys and worm and wormwheel.
"Scientific American Supplement, No. 795, March 28, 1891" by Various
FRICTION OR GEARED MINING & QUARRY HOISTERS.
"Scientific American, Volume XXIV., No. 12, March 18, 1871" by Various
Grooved friction gears 71 66.
"Practical Mechanics for Boys" by J. S. Zerbe
The controlling leaders being out of gear the machine did not run smoothly: there was nothing but friction and tension.
"Napoleon's Marshals" by R. P. Dunn-Pattison
At the normal gear there is of course no additional friction.
"Encyclopaedia Britannica, 11th Edition, Volume 3, Slice 7" by Various
In America friction gearing has been tried, but I do not know with what success.
"Wrinkles in Electric Lighting" by Vincent Stephen