~3 



FOUNTAINS. 



197 



turned upwards as in fig. 140, the jet will be 

 directed upwards and reach a height which depends on 



m 



FIG. 140. 



depth of the orifice below the 



surface of the liquid. The ascending 



jet would rise to the level of the 



liquid were it not for the resistance 



of the atmosphere and the friction of 



the liquid particles against the sides 



of the vessel and the edges of the 



orifice ; these resistances diminish 



the elevation of the jet considerably, 



especially when the vessel is not 



very wide, as in fig. 140, or when 



part of it is formed by a long narrow 



tube, as in fig. 141. In ordinary 

 | fountains the orifice from which the jet escapes is con- 

 nected by a series of tubes, often of great length, with 



a reservoir which is placed at some height above the 

 i orifice; the elevation of the jet is in such a fountain 



considerably less than the height of the reservoir from 



which it issues, in consequence of the great friction 



which takes place within the conducting tubes. 



FIG. 141 (| real size). 



