The tinman's manual and builder's and mechanic's handbook : designed for tinmen, japanners, coppersmiths, engineers ... with compositions and receipts for other useful and important purposes in the practical arts (1861)
Butts, I. R. (Isaac Ridler), 1795-1882 · Boston : I.R. Butts & Co. · leaf 26
arcs NO and NJ, having the points of contact at S andS ; on this tangent line erect a perpendicular passing through thepoint N produced until it intersects the line BE produced ; then placeone foot of the dividers on the point of intersection R and span themover the dotted line to the point T, and… … Mark out the length and depth of the elbow, ABCD ; draw a semi-circle at each end, as from AB and CD ; divide each semicircleinto eight parts ; draw horizontal lines as shown from 1 to 1, 2to 2, &c. ; divide the circumference or length, ACBD, into sixteenequal parts, and draw perpendicular…
