382 DISTANCE. 



Q. In a long straight STREET, WHY do the 

 houses seem to be SMALLER and smaller the FURTHER 

 they are OFF ? 



A. Because the further any house is 

 off, the more acute will be the angle made 

 by its perpendicular height with our eye. 



Thus in the last figure 



If AB be a house at the top of the street, its per- 

 pendicular height will be that of the line AB. 



If CD be a house at the bottom of the street, its per- 

 pendicular height will appear to be that of E F. 



Q. Why does a man on the TOP of a MOUN- 

 TAIN or church spire seem to be no BIGGER than a 

 CROW? 



A. Because the angle made hy the 

 perpendicular height of the man (at that 

 distance) with our eye, is no bigger than 

 the perpendicular height of a crow close 

 by. 



A 



Let AB be a man on a distant mountain or spire, 

 and C D a crow close by : 



The man will appear only as high as the line C D, 

 which is the height of the crow. 



