248 LAWS OF REFLECTION AND REFRACTION. 



fied curvature. He has only to consider in what way solid 

 bodies, impelled against such a surface, would rebound from 

 it. Thus a concave mirror acts to gather together parallel 

 rays falling upon it, just as a shower of peas falling upon 

 the inner sides of a saucer or a bowl would rebound to- 

 ward the.centre. On the other hand, a convex mirror will 

 reflect rays in a divergent direction, just as peas falling in 

 a shower upon the outside of a bowl, placed bottom up- 

 ward, would rebound away from it in every direction. 



