510 



PROFESSOR CHRYSTAL 



suppose the pressure disturbance to reach the negative end of the lake just after the 

 extreme amplitude there has reached a maximum ; so that t 1 = ir\n v In this case 

 we have 



3^ = -A 1 '=4©3^; 



In particular, the maximum increase of the extreme amplitude is l"2539p, corre- 

 sponding to y;T x /2a = T82. Since T 1 = 14"5 m , this would give for the velocity of 



w 



48 

 46 

 •f* 

 12 

 40 

 38 

 36 

 34 

 32 

 30 

 28 

 26 

 24 

 22 

 20 

 18 

 16 

 ■M 

 12 

 10 

 08 

 06 

 04 

 02 

























3/fy 

 '36 



































































































































































































































































































































































































in 



















1 -4- 



a 



■8 10 12 M 16 18 



Fig. 23. 



20 22 29 

 2 082 



V- = 1-51 



26 28 30 32 



propagation of the pressure disturbance which produces the greatest effect about 45 

 (mile/hour). 



If we put Tj = 0, and suppose vT 1 <2a, we get 



3&J = A 1 '= - |®3p ; 



3tj = BZ/^jTij = ^dp/hjUi ; 



and the maximum value of d/q is 75dp, the corresponding value of v being about 12 

 (mile/hour). 



