AND OTHER WATER WAVES 33 



The greatest length (calculated from the 

 observed period) is 15.4 times the greatest height. 



Lake Superior 



On Lake Superior waves have been carefully 

 measured from the shore by Colonel D . D . Gaillard, 

 Corps of Engineers, U.S.A. For the size of the 

 waves out in the deep water of the lake, he has, 

 however, had to obtain evidence from the captains 

 of vessels. He writes : l 



" As the result of inquiries of vessel captains 

 who have navigated Lake Superior for many years, 

 and who have, in some cases, made a special note 

 of the fact that in unusually severe storms the 

 hlorizon could not be seen from the wheelhouse 

 when the ship was in the trough of the sea, on 

 account of adjacent wave -crests, it seems probable 

 that during unusually severe storms upon Lake 

 Superior, which occur only at intervals of several 

 years, waves may be encountered in deep water 

 of a height of from 20 to 25 feet and a length of 

 275 to 325 feet." 



He adds that the waves on Lake Superior are 

 larger than occur on any other of this chain of great 

 lakes. 



i " Wave Action in Relation to Engineering Structures " 

 (Washington Government Printing Office, 1904), p. 82. 



3 



