Educational woodworking for home and school (1908)
Park, Joseph C · New York, MacMillan · leaf 309
8^ Constant (equable) spiral. Variable(qeometric)spiral. Involute on a 3(]Udre. (spiral of A.rchlmcdes) ^Circle in centre i» the eye) AB AB.etC radium vector.Pitch-V- Fig. 259.— Curves and spirals. … T=thumbtack.S-strir.qPUT*T*. arethe foci (focuses).
Manual training · Woodwork
Internet Archive · University of Toronto, Robarts Library · Public Domain Mark 1.0. Free to use for anything.
