Zon, Raphael, 1874-1956, Graves, Henry Solon, 1871-1951 · Washington, D.C. : U.S. Dept. of Agriculture, Forest Service · leaf 44
Fig. 7.—Clements photometer, a, Perspective view of the photometer in use; 6, rearview of the inner case ; c, perspective view, showing the inside construction. at E, care being exercised that the strip fits into the groove all around.The strip is then drawn tight and the ends are wedged into the…
Plants Effect of light on · Trees Growth · Light Effect on trees · Tree growth
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