John Jacob Holtzapffel · digital reprint by www.CircuitousRoot.com · leaf 617
may be briefly referred to, together with some other results obtained from them. The paper is held by single sheets in a tympan chuck, or as a block of many sheets attached to the face of an ordinary wood chuck. The tympan chuck fig. 568, has a large flat flange with a circular frame hinged to its… … disc of a little larger diameter are both surfaced, some twenty sheets of smooth drawing paper are then placed against the surface of the chuck and compressed by the disc advanced by the point of the popit head. The edge of the disc and the corners of the paper are next turned off to the diameter…
Ornamental turning
Internet Archive · Dr. David M. MacMillan · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten06unit-882-0.webp)
