The sheet-metal worker's guide : a practical handbook for tinsmiths, coppersmiths, zincworkers, etc., comprising numerous geometrical diagrams and working patterns, with descriptive text (1888)
Crane, W. J. E. (W. J. Eden) · London : Lockwood and Son · leaf 79
67 THE SPHERE. chy d i, and set off in the arc c h the same number of equal parts as are in 14, 7 c towards A. Through the last of these, as 14, draw 14^, and through all the other parts similar lines converging to g ; … Fig. 59. j d is the covering of the part, c d f 14. The whole surface of the hemisphere may be covered by a series of such parts, the quadrant being divided into equal parts, to give an equal depth to the covering surfaces.
Sheet-metal work
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
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