New York, Industrial Publication Company · leaf 386
required, only on one hr ie mas sn ; out by being warmed, will have a knife- single disc; this is placed in the centre, and anumber of smaller pieces of glass edge perfect in the extreme. planted round the circumference to sup- port the figure, the whole being ground as one. But in the lenses to… … The same rules for guarding the extreme the diameter of the cell in which the lens edges of lenses should be observed, as de- is to go. seribed in prism-work, shown by the fol- venient. lowing examples. Fig. 8a, represents a Fee a erg et eee plano-convex lens which has been made large to enter the…
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