34 WAVES OF THE SEA 



In the Duluth Canal at the western end of Lake 

 Superior Colonel Gaillard during 1901 and 1902 

 frequently measured waves 200 feet in length, 

 occasionally 250, and once 275 feet, in a depth 

 of not more than 27 feet of water. The velocity 

 of such waves is reduced in water of this depth 

 and they close in upon one another, their wave- 

 length diminishing. The measurements taken by 

 Colonel Gaillard in somewhat shallow water there- 

 fore show that the estimates of wave-length made 

 by the captains of vessels were not excessive, and 

 that we may safely say that a length of 300 feet 

 is attained during exceptionally severe storms by 

 the waves of Lake Superior. The possible length 

 of fetch of wind and length of run of the waves 

 at Duluth is 298 statute miles or 259 nautical miles, 

 so that the greatest wave-length is 1-5 248th of the 

 length of the lake, and if the average wave-length 

 of the series be 150 feet, there would be 10,496 

 successive waves simultaneously between windward 

 and leeward shore. Thus again we find the steady 

 growth of wave-length with the length of the sheet 

 of water, the increase of wave-length taking place, 

 however, more slowly. 



Taking the height of the waves during severe 

 storms on this lake as 22^ feet and their length as 

 300, we find that the length is 13.3 times the 



