Brewster, David, Sir, 1781-1868, Bache, A. D. (Alexander Dallas), 1806-1867 · Philadelphia : Lea and Blanchard · leaf 84
d black, is beyond the middleof the red; D is in the orange, and is a strong double line,easily seen, the two lines being nearly of the same size, andseparated by a bright one; E is in the green, and consists ofseveral, the middle one being the strongest; F is in the blue,and is a very strong line;… … space, and half-way between A and B is a group of seven oreight, tbrming together a dark band. Between B and C thereare 9 lines; between C and D there are 30; between D andE there are 84 of different sizes. Between E and b there are24, at b there are three very strong lines, with a fine clearspace…
Optics
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