Hasluck, Paul N. (Paul Nooncree), 1854-1931 · London ; New York : Cassell and Co. · leaf 69
these arches they would be struck from the same centres, so as to give parallel curves. Fig. 118.—Elliptical Arch. Fig. 119.—Lancet Arch. A true elliptical arch cannot be struck from centres, as it is a conic section, but a very fair one may be set out as shown in Fig. 118. Divide the springing… … The lancet arch (Fig. 119), so common in Early English archi- tecture (A.D. 1189-1307), has the centres on the springing line, and the radius used is equal to one and a-half times the span. The equilateral arch (Fig. 120) is the easiest of all to draw, the radius being equal to the span. It was…
Mechanical drawing
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
