Practical draughtsmen's work, with numerous engravings and diagrams (1903)
Hasluck, Paul N. (Paul Nooncree), 1854-1931, ed · Philadelphia, D. McKay · leaf 34
Fig. 38.—Spring Bow Poncil. … 39.—Spring Bow Pen. Bows (Fig. 36) are used for describing smaller circles, and thesemay be obtained also either single or double jointed, or withplain or needle points. Double-jointed bows, with needle points,arc well worth the extra cost. Spring bows are used for making small circles. They are…
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
