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 21
distance from the middle of the chord DFE to themiddle of the subtending arc DGE, will be the circumference sought. TO FIND THE AREA OF THE SECTOR OF A CIRCLE. Rule. Multiply the length of the arc DGE by its radius DC,and half the product is the area. The length of the arc DGE equal 9^ feet, and… … To enable machinists to enlarge or reduce machinery wheels with-out changing their respective motion. First, describe two circles AB and CD the size of the largest wheelswhich you wish to change to a large or small machine, with thecentre P of the smaller circle CD on the circumference of the…
