SEEING. 133 



the judgment concerning magnitude begins to be rectified. 

 If we judge solely by the eye, and have not acquired the 

 habit of considering the same objects to be equally large, though 

 seen at different distances, the nearest of two men, though of 

 equal size, would seem to be many times larger than the 

 farthest. But we know that the last man is equally large with 

 the first ; and, therefore, we judge him to be of the same 

 dimensions. Any distance ceases to be familiar to us, when 

 the interval is vertical, instead of being horizontal ; because 

 all the experiments by which we usually rectify the errors of 

 vision, with regard to distances, are made horizontally. We 

 have not the habit of judging concerning the magnitude of 

 objects which are much elevated above or sunk below us. 

 This is the reason that, when viewing men from the top of a 

 tower, or when looking up to a globe or a cock on the top of 

 a steeple, we think these objects much smaller than when seen 

 at equal distances in a horizontal direction. During the night, 

 on account of the darkness, we have no proper idea of dis- 

 tance, and, of course, judge of the magnitude of objects solely 

 by the largeness of the angle or image formed in the eye, 

 which necessarily produces a variety of deceptions. When 

 travelling in the night, we are liable to mistake a bush that is 

 near us for a tree at a distance, or a distant tree for a bush 

 which is at hand. When benighted in a part of the country 

 with which we are unacquainted, and of course unable to 

 judge of the distance and figure of objects, we are every mo- 

 ment liable to all the deceptions of vision. This is the origin 

 of that dread which some men feel in the dark, and of those 

 ghosts and horrible figures which so many people positively 

 assert they have seen in the night. Such figures are com- 

 monly said to exist in imagination only ; but they often have 

 a real existence in the eye ; for, when we have no other mode 

 of recognizing unknown objects but by the angle they form 

 in the eye, their magnitude is uniformly augmented in propor- 

 tion to their vicinity. If an object at the distance of twenty 

 or thirty paces, appears to be only a few feet high, its height, 

 when viewed within two or three feet of the eye, will seem to 

 "be many fathoms. Objects in this situation must excite ter- 

 ror and astonishment in the spectator, till he approaches and 

 recognizes them by actual feeling ; for, the moment a man 

 examines an object properly, the gigantic figure it assumed in 

 the eye instantly vanishes, and its apparent magnitude is re- 

 duced to its real dimensions. But if, instead of approaching 

 an object of this kind, the spectator flies from it, he retains 

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