Warren, Samuel Edward, 1831-1909. [from old catalog] · New York, J. Wiley & sons · leaf 202
the space on the retina, illuminated by rays from the spaceAB on the object. Now remove AB to double the distance ACviz. to AB, and the point B will be imaged at r, one-fourth asbrightly as at r. But Rr is half of Rr, and hence the area, ofwhich Rr is the diameter, is one-fourth as large as that…
Shades and shadows
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