Compton, Alfred G. (Alfred George), 1835-1913 · New York : J. Wiley & Sons · leaf 142
128 FIRST LESSONS IN METAL- WORKING. drill.'^ The slot is commenced by boring two holes … Fig. 71. bnt the essential pi'in- ciple of all is the same. The work to be drilled rests, at on blocks supported on the frame-work B, which may be screwed to the bench. A screw (7, which must be turned by hand as the boring progresses, or else a lever worked by the hand of an assistant, presses the…
Metal-work
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