A text-book of physiology for medical students and physicians . hat will enable us to throw theright-eyed picture on the right eye and the left-eyed picture onthe left eye constitutes a stereoscope. Many different forms ofstereoscope have been devised; the one that is most frequently A i used is the Brewster stereoscope :\ \ / represented in principle in Each eye views its corre-sponding picture through acurved prism. The sight of theleft-eyed picture is cut off fromthe right eye, and vice versa, bya partition extending for somedistance in the median prisms are placed with t
A text-book of physiology for medical students and physicians . hat will enable us to throw theright-eyed picture on the right eye and the left-eyed picture onthe left eye constitutes a stereoscope. Many different forms ofstereoscope have been devised; the one that is most frequently A i used is the Brewster stereoscope :\ \ / represented in principle in Each eye views its corre-sponding picture through acurved prism. The sight of theleft-eyed picture is cut off fromthe right eye, and vice versa, bya partition extending for somedistance in the median prisms are placed with theirbases outward and the rays oflight from the pictures are re-fracted, as shown in the diagram,so as to aid the eyes in converg-ing their lines of sight upon thesame object. The prisms alsomagnify the pictures pictures are mountedusually for this instrument so thatthe distance between the sameobject in the two pictures is about 80 nims.—greater, therefore, thanthe interocular distance. A simple form of stereoscope that is very )>B. Fig. Diagram to illustrate theprinciple of the Brewster stereoscope(Landois): P and P, the prisms, a, b,and a, 0, the left-and ri^ht-eyed pictures,respectively, b, /3, being a point in theforeground and a, a, a point in the back-ground. The eyes are converged andfocused separately for each point as inviewing naturally an object of three di-mensions. BINOCULAR VISION. 373 effective and interesting is sold under the name of the two pictures in this case are approximately superposed, but theoutlines of one are in blue and the other in red. When looked at,therefore, the picture gives an ordinary flat view with confusedred-blue outlines. If, however, one holds a piece of red glass infront of the left eye and apiece of blue glass in front of the right eye,or more conveniently uses the pair of spectacles provided whichhave blue glass on one side, red on the other, then the picture standsout at once in solid re
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Keywords: ., bookautho, bookcentury1900, bookdecade1910, booksubjectphysiology
