Appleton's cyclopædia of drawing, designed as a textbook for the mechanic, architect, engineer, and surveyor (1866)
Worthen, William Ezra, 1819-1897, [from old catalog] ed, Appleton, firm, publishers, New York. (1866. D. Appleton & co.) [from old catalog] · New York, D. Appleton and company · leaf 31
onsist-ing of two rulers connectedby two bars moving onpivots, and so adjusted thatthe rulers, as they open,form the sides of a ]3aral-lelogram. The edge of oneof the rulers being retainedin a position coincidingwith, or parallel to a given line ; the other ruler may be moved, and linesdrawn along… … Fijr. 40. SWEEPS AND VAKIABLE CURVES. For drawing circular arcs of large radius, beyond the range of the or-diiuiry compasses, thin slips of wood, termed sweeps, are usefully employed, of which one or both edo-es o are cut to the required circle.For curves which are notcircular, but variously…
