88 



MR RUSSELL'S RESEARCHES IN HYDRODYNAMICS. 



2500 feet, it had been deflected thi'ough double that quantity. The spaces mark- 

 ed as the distances of generation are exclusive of the distance between the sta- 

 tions A and B = 700 feet. 



Experimental Station. — Hermiston, 

 Space traversed by the wave ft-om A to B : 



700 feet. 



60. \ 



61. ) 



Wave generated close 

 to A. 



Wave generated 500 

 feet from A^ 



Wave generated 1000 

 feet from A, 



Wave 1500 feet from A, 

 Wave 2500 feet from A, 



Height B. 



Inches. 



5 



5 

 6 

 5 



4.6 

 2 



2 

 2 

 2 

 2 



2 



2 



Time. 



Mean Velocity = 11.359 feet per second ^= 

 7.69315 miles. 



Mean Velocity := 11.290 feet per second =: 

 7.553010 miles. 



Mean Velocity = 11.200 feet per second =: 

 7.49280 miles. 



63.5 Mean Vel. = 11.023 ft. per sec. = 7.37438 miles. 



64.6 Mean Vel. = 10.852 ft. per sec. = 7.259988 m. 



In these examples no particular velocity was employed for generating the 

 wave. A vessel was put in pretty rapid motion by a couple of horses, over a 

 space of about 500 feet, and was then suddenly stopped, so as to allow the water 

 it had set in motion to move forward before the vessel in the form of a wave, and 

 the velocity of the wave w^as then measured from a mark at a station of observa- 

 tion to that of another station whose distance was known. These examples which 

 have been given comprehend the waves of a considerable variety of velocities of 

 motion. The following observations were made with this view alone, of deter- 

 mining whether the velocity of the vessel had any influence on that of the wave, 

 from which the influence appears to be insensible. 



Exper. 

 58. 



59. 



60. 



61. 



62. 



63. 



Space 700 feet. 



'^elocity of Boat. 

 Miles per hour. 



/ 6 \ 



Time. 

 Sees. 



62 



3 



61 



10 



61 



< 



7 



> 



62 





7 





62 





. 4, 





61.6 



From these experiments it appears that the velocity of the wave, is that ac- 

 quired by a heavy body falling through a space equal to half the depth of the 

 fluid, and that the velocity appears to vary with the magnitude of the wave very 

 nearly in the ratio which is obtained by supposing the depth of the fluid increased 

 by a quantity equal to the height of the wave, so that the variations of velocity 



