If A B be a house at the top of the street, its perpendicular height will be that of the line A B.
If C D be a house at the bottom of the street, its perpendicular height will appear to be that of E F.
Q. Why does a man on the top of a mountain or church spire seem to be no bigger than a crow?
A. Because the angle made by the perpendicular height of the man (at that distance) with our eye, is no bigger than the perpendicular height of a crow close by.
Let AB be a man on a distant mountain or spire, and CD a crow close by:
The man will appear only as high as the line CD, which is the height of the crow.
Q. Why does the moon appear to us so much bigger than the stars, though in fact it is a great deal smaller?
A. Because the moon is very much nearer to us than any of the stars.
