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56 Accommodation: Study of Images |
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Fig. 25 Arrangements for Holding the Head of the Subject Steady While Images Were Being Photographed
CM, concave mirror; F, forehead rest; C, condenser MP mouthpiece; Pr, perimeter. ' '
a clearer and more constant image, but it still was not sufficiently reliable to be measured. To Helmholtz the indistinct image of a naked flame seemed to show an appreciable change, while the images obtained by the aid of the diaphragm showed it more clearly; but I was |
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