Author: :
Title: DBS Double Helical Gear and its application as a high effeciency speed reducer.
Description: Huddersfield: David Brown & Sons. [n.d., ca. 1920?]. Small 4to, 21.8cm. Pp. 136, 65 photos (mostly full-page) and figs., subject index. Paperbound, orig. printed wrappers. Stain on rear cover, some light traces of use but a very good copy yet. Scarce.

Keywords: