| Show curiosities OF SEEING remarkable itrich show how easily iho tho 1 ayn y Is I 1 deceived somo some very remarkable experiments which any onedith one with a little care may repeat for himself hims alf havo have recently been made on the perspective effects of color it if on a screen of black velvet placed about 10 feet away largo letters are pasted come some blue and some red tho the letters will not appear to be at an equal distance from tho the eyes to some per tons eons the rod lettera letters will seem nearer than the blue lett lettero cro chile I 1 to others 1 N I 1 I 1 be 69 contrary i ari effect w will M be manifested fea tho the blue letters appearing nearer than tho the red ones to produce this curious effect both eyes must be used when ono eye is closed tho the letters are all seen at tho the samo same distance on opening tho the other eyo eye ono one set of letters immediately appears to take a position in advance of the others the explanation offered is that a sort of stereoscopic effect is produced in the eyo eye itself depending on color the i imago 14 of a bino blue object is shifted by the eye toward one ono side and that of a red ob object J act toward tho the other side the causo of the shifting being tho the eccentricity of tho the pupil of the eye this eccentricity may bo be increased by holding a black screen close to the eye so as to cover one half of tho the pupil the effect is best viewed by screening both pupils at the same time ifon if on looking at blue and red letters on a black background placed 10 or 13 12 feet away you see tho the red letters nearer than the blue ones screen off one half of tho p pupil u of each eye on the outside and you will then seo see tho the red letters detira behind tho the blue ones if you screen tho the pupils on tho the side toward tho the nose you will see tho the red letters advance apparently still farther ahead of tho blue letters if on tho the other hand band yon you naturally see tho the blue in advance screen the inner side of your pupils and tho the red will come to tho the front it has lately been shown by dr A D waller that very beautiful effects can bo be produced with ono one eye alono alone when instead of letters rod red or blue rings aro are pasted on a background of tho the opposite color placing red rings on blue paper and using tho the right 0 oye Y 0 with tho the inner side of the pupil c covered ov ered tho the appearance is that of circular red hillocks resting upon a blue ground to produce this effect in its highest degree tho the paper should bo be held to the left and sloping in that direction when tho the outer sido side of tho the pupil is screened the red ring become circular trenches in tho the blue paper youths Com companion ranion |
