. Bird lore . a-tion, and the Bluebirdshousehold duties continuedas though nothing had hap-pened. A year after this nest wasphotographed another nestwas selected for an experi-ment in the use of mirrors,whereby the tree was notdamaged; no possible harmcame to this bird or nest,and the eggs were photo-graphed exactly as they are innature. The nest was builtin a cavity in a cherry treefive feet from the entrance was about fourinches in diameter and wasfourteen inches from the nestat the bottom of the tree is shown in Fig. 3,with an arrow pointing tothe entrance to the nest-ho
. Bird lore . a-tion, and the Bluebirdshousehold duties continuedas though nothing had hap-pened. A year after this nest wasphotographed another nestwas selected for an experi-ment in the use of mirrors,whereby the tree was notdamaged; no possible harmcame to this bird or nest,and the eggs were photo-graphed exactly as they are innature. The nest was builtin a cavity in a cherry treefive feet from the entrance was about fourinches in diameter and wasfourteen inches from the nestat the bottom of the tree is shown in Fig. 3,with an arrow pointing tothe entrance to the nest-hole. Fig. 4 illustrates themethods used and Fig. 5 thephotograph obtained. The rays of the sun werereflected from the mirror onthe ground to the mirror inthe entrance, then down upon the nest, back again to the mirror,and finallyinto the camera. In this way a reflection of the nest and eggs on the mirrorin the entrance was photographed, the real nest being fourteen inches be-low where it appears in the TREE CONTAINING BLUEBIRDS NEST, SHOWINGMIRROR IN POSITION 94 Bird- Lore The adjustment of the mirrors was a very delicate operation, and anumber of negatives were made that did not contain the reflected nestbecause of a very slight error in directing the rays of light.
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Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, booksubjectorn
