Geometrical Dividers for Lines and Circles

摘要

14,712. Cressey, C. July 11. Dividing-instruments.-A combined divider for circles and straight lines comprises groups of concentric lines B1 and groups of parallel lines B. If the circumference of a circle is to be divided, the centre E is placed over the centre of the circle and the divisions pricked through or otherwise marked off from the curved lines F. Straight lines as D are divided in the usual way by laying them raking across the parallel lines B.