in length. It is probable that waves never attain that size in Lake Erie. 

 According to Gaillard the highest waves at Buffalo were reported to be 10 

 feet (3.0 meters) in height. 



Seiches 



Rapid fluctuations of level in the Great Lakes were noted at a very 

 early time, certainly before the middle of the seventeenth century (Thwaites, 

 1898, p. 6l)£./. Their cause was a subject of speculation for many years; 

 some regarded them as tides comparable to those in the ocean, while others 

 denied the existence of tides. It is now kno^/m that the fluctuations were 

 the result of seiches. 



During the present investigation, no study was made of seiches and the 

 subject will not be discussed in detail. The reader interested in seiches in 

 the Great Lakes may refer to the following papers: Whiting (I83I) , Whittlesey 

 (1851 and 1875), Lachlan (l855), Comstock (1872), Le Gonte C188U), Perkins 

 (1893), Harrington (l895), Denison (1897), Borman (1912), and Crohurst and 

 Veld^e (1927). In addition the' following concern Lake Erie especially: Reed 

 (1899), Henry (1899 and 1902), Harris (1902), Endrfts (1908), McLaughlin (1911), 

 Jackson (1912), Farwell (1925), Hayford (1922), Krecker (1928 and 1931), 

 Parmenter (1929),and Green (1933). 



Our knowledge of the periods and amplitudes of seiches in Lake Erie may 

 be summarized briefly as follows: The uninodal longitudinal seiche has a 

 period of very nearly ll|.2 hours and the uninodal transverse seiche a period 

 of about 2.6 hours. There is some evidence of the presence of binodal, tri- 

 nodal and quadrinodal longitudinal seiches of 8.8, 5.7 and U.l hours respec- 

 tively. There is abundant evidence for the existence of other seiches of 

 shorter periods, operating along more localized axes. The amplitude of the 

 seiches varies from a few centimeters to nearly 3 meters, and for any single 

 type of seiche varies according to the magnitude of the original disturbing 

 force. 



Tides 



Tides in the Great Lakes are so small that they must be considered as 

 minor disturbances of the levels. Seiches commonly cause fluctuations sev- 

 eral times greater than the highest tides. Tides have been observed at 

 Milwaukee and Chicago in Lake Michigan, and at Duluth and Marquette in Lake 



2/ The Jesuit Relations contain many notes on natural phenomena observed by 

 the missionaries (see Index, Vol. 72 and 73). For others see the index 

 to l&sconsin Historical Collections, Vol. XXI. The T«^ole subject of early 

 exploration on the Great Lakes is treated in detail by Kellogg (1925) • 



38 



