Mechanical drawing; a treatise on the drawing of mechanical and machine details (1920)
Jones, Franklin Day, 1879-1967 · New York, The Industrial press; [etc., etc.] · leaf 322
hod of varyingthe light intensity without destroying the uniformity ofdistribution. Adjustable Drop-light and Reflector. — The most commonsystem of artificial illumination in drafting-rooms is by meansof drop-lights and reflectors, either 16- or 32-candlepowerlamps being used. One 16-candlepower… … Fig. 10. Light held in Adjustable Bracket injurious to the vision. It has been found that two 16-candle-power lamps are preferable. One of these should be placed atthe extreme left and the other a little at the right of the centerof the board. If one of the lamps casts objectionable shadows,it can…
Mechanical drawing
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