248 



HERO'S FOUNTAIN. 



may then be filled by simply removing /; or water 

 may be poured into the shallow dish and allowed to 

 run down through c into b- 7 the whole apparatus is 

 then inverted and the water passes from b through d 

 into a. When the upper vessel is thus filled, water is 

 poured into the shallow dish; it flows through c into 

 /;, and the pressure of this column of water, acting upon 



FIG. 170 (A, B, ^g real size; C, an. proj., ~ real size}. 



the air in &, is transmitted through d to -the top of $, 

 where it acts upon the water and makes it jet out; the 

 height of the jet is represented in the figure as much 

 less than it actually is; for if it were not for the resist- 

 ance of the atmosphere and the friction, the liquid 

 would rise to a height above the surface of the water 

 in the dish equal to the difference in the level of the 

 water in a and b. When the water in a sinks below 



