John Jacob Holtzapffel · digital reprint by www.CircuitousRoot.com · leaf 438
412 ORNAMENTATION OP DOMES the back is slackened and the work raised or lowered by the mainscrew until the point of the tool, when advanced to one and the same depth, just touches the work equally both at its cir- cumference a, when the chuck is vertical, and at the center mark b, when it is… … point a, fig. 447, and while so retained by the lever or the collar, the mandrel is turned one quarter round towards the operator by the left hand laid on the pulley, when the point of the tool scribes a fine line on the work from a to b. Inspec- tion of this trial line shows whether the lateral…
Ornamental turning
Internet Archive · Dr. David M. MacMillan · Public Domain Mark 1.0. Free to use for anything.
