Hall, Edwin Herbert, 1855-1938 · New York, H. Holt and company · leaf 108
from part ofthe flame AB, but not from all of it, will appear a partiallyshaded ring, PSSP, around the central area of totalshadow. This ring forms what is known as the penumbra(from two Latin words meaning almost and shadow). On account of the comparatively large size of mostsources of light most… … Fig 60. may compare the dim and indistinct shadows of the leavesof shade-trees exposed to the sun, with those cast by thesame objects exposed to the electric light at night, in whicheven the serrated margins of the leaves are sometimes clearlyoutlined. 98. How Light Weakens with Distance. Law of…
Physics
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
