Edwin Harrington, Son & Co.
Illustrated catalog given to Lamar Lyndon ca.1890.  The firm was located at North Fifteenth Street & Pennsylvania Avenue, Philadelphia, Pennsylvania.
Webpage copyright © George Langford 2010
Machine Tools, ca. 1890 illustrated catalog
Edwin Harrington Gear Cutting Machine, pages 105-107
We have 9 automatic gear-cutting machines, on which we can cut Spur, Worm, Bevel and Spiral gearing; eight feet diameter or less.
Also, rack-cutting machine, on which can be cut any required length and pitch.  We are prepared to estimate for gear and rack cutting, all sizes and description.  By the aid of special machinery we are prepared to furnish planed BEVEL GEARS with the curves of the teeth theoretically correct.  This method admits of long faces, good contact. and smooth running, thereby increasing durability.  For patterns to cast from, and in places where high speed is required, gearscut in this manner are especially desirable.
Edwin Harrington Gearing, page 107