146 HYDROKINETICS. 



FIG. 86. 



cal distances are passed over, the initial velocity of an ascend- 

 ing body is the same as the final velocity of a falling body. 

 ( 13&) Hence, the velocity of the water as it issues at V ia 

 the same that it would acquire in freely falling the vertical 

 distance h V. This velocity is caused by lateral pressure. 

 This lateral pressure will be the same at P, which is at the 

 same distance below the level of the liquid. Therefore, the 

 velocity at P will equal the velocity at V. Hence the fol- 

 lowing law: The velocity of a stream flowing from 

 an orifice is the same as that acquired by a "body 

 freely falling from a height equal to the head cf 

 the liquid. 



(a.) The head is the vertical distance from the centre of the 

 orifice to the surface of the liquid. 



(6.) With what velocity will water issue from an orifice 144.72 ft. 

 below the surface of the liquid ? 



8 = &t* ( 128 [3].) 

 144.72 = 16.08** .'. 9 = t-. 



3 = t. 



9 = fft. (% 128 [1].) 



= 82.16 ft. x 8 = 96.48 ft. Am. 



