16 



FLUCTUATIONS OF LEVEL 



The same southerly breeze and eloudy weather existed at the close as at the 

 commencement. 



The coast is visible from the pier each way one-fourth of a mile, over a clear 

 sand beach. 



At the moment of each influx a low wave broke on the shore along the whole 

 field of view, and at each depression the water retired from one to three rods on 

 the beach. This occurred everywhere at precisely the same instant. It had the 

 appearance of a succession of undulations too slight and broad to create a visible 

 swell on the surface coming directly upon the shore. The waves must have been 

 parallel to the coast line and not oblique to it, or they would not have arrived at 

 the same moment. If the crest of the undulations made an angle with the shore, 

 the breaking of the water would have been progressive along the beach, as in tlie 

 case of oblique waves. 



Both the flood and ebb occurring as nearly as T could determine along a line 

 of half a mile in length at the same time, the swell must have moved directly 

 toward shore. On the 2d and 3d of this month (October, 1854) a destructive 

 storm occurred, beginning at the east, changing to northeast and north, and finally 

 to northwest, with heavy rain. 



On my return to the Lake in the afternoon of the 11th, the movement was as 

 active as in the morning. There had been no cessation during the day. 



Eecord of Fluctuations. October 11th, 1854. 



This table shows greater rapidity of movement than that for the morning. The 

 readings were made in the creek at the usual place, where the range from high to 

 low level, as might be expected, Avas somewhat less than in the open Lake at the 

 pier. As a general rule, it will be observed that the pulsation which is longest in its 



