lopograpMcal Features of the IVew Haven region. 93 



mean tide, then the slope normal for the whole of the plain to the 

 southern part of the Beaver Pon<l meadows, a distance of 2f miles, 

 would not have been over six feet a mile. 



h. From the waves alone. — The bay flats are a direct continuation 

 of the flood-grounds or lower flats of the rivers entering the bay; and 

 yet the former are leveled off at one-third tide, or lower, while the 

 river flats and those of any sheltered coves may be very near high- 

 tide level. The flats in the bay, like those outside, are washed by 

 the waves and hence their lower level. If the surface is at one-third 

 tide, as is the case with the flats off West Haven Point, there is then 

 a difference of about 4 feet between their level and that of the flats 

 or meadows along Mill river and the other rivers of the region. Con- 

 sequently, in a rise of the land the surface of the river fiats would he 

 3 or 4 feet higher than that of the unprotected hay flats. 



When, however, the river flats are wet meadows, made of deep 

 muck and oozy mud, they will dry and sink, and may thus lose all 

 their excess of height, unless the flats are of so soft a mud as to set- 

 tle equally. In the latter part of last century the tides were mainly 

 shut out from the upper pai't of West River by a dam along the line of 

 the bridge of the Milford Turnpike (see map) and, as a consequence, 

 the meadow north of the dam is l^ feet lower than that to the soiith. 

 Those who know the history of the changes there attribute the dif- 

 ference of level to a fall in the surface from loss of water beneath ; 

 and this was doubtless the true cause. But, in the case of the river 

 flats of the Champlain era, there is no evidence that they were to2:)ped 

 by muck meadows ; for in all the sections exposed to view they 

 carry their sandy layers quite to the top. We may therefore reason- 

 ably assume that 3 to 4 feet of the excess in the height of the part of 

 the plain leveled hy the river floods above that of those along the bay, 

 are to be attributed to the cause here explained. 



c. Slope as a comhined result of (a) the increasing depth of the 

 waters southxoard over the shalloio horder of the hay region^ and (b) a 

 decrease southward in the supply of sand — the deposits as they extend 

 southward consequently rising to a less and less height beneath the 

 water's surface. The waters dropping their sands as they flow on 

 through the bay would necessarily have had less for deposition about 

 its outer portion. Part of the diminishing elevation of the plain in 

 West Haven toward the Sound (p. 89), and j^erhaps something of that 

 of Oyster Point, may have this explanation ; and the latter may have 

 been the principal one of the two causes here included. 



