287 



facts were shown to he wanting, we need not rloiiht that 

 Hingham has participated in the slight downward movement of 

 which we have satisfactory evidence in other parts of the 

 Boston Basin. All the evidence now at hand indicates that 

 the land has been nearly if not quite stationary for a long 

 period; and if, as has been supposed, a subsidence is still in 

 progress, it must be extremely slow. 



Tlie erosive action of the streams of Hingham during post- 

 glacial time has been insignificant. The almost entire absence 

 of rapids indicates that the streams have to a very large extent 

 i-egained the preglacial drainage lines ; and in consequence we 

 rarely find them now eroding the hard rocks. Weir River, 

 below Lcavitt Street, is, of course, a notable instance of 

 diverted drainage, and the artificial fall where the river issues 

 from Foundrv Pond is almost the onlv susrsestion of a cascade 

 character observed in any of the streams of Hingham. The 

 general absence of ledges in the valleys is, obviously, explained 

 by the strong preglacial elevation of the land, during which 

 the valleys were, in many cases, cut down below the present 

 level of the sea. Marine erosion in postglacial times is practi- 

 cally limited to the drumlins about the harbor and the sand- 

 plains and kames bordering Weymouth Back River. 



The principal salt marshes of Hingham are the Home 

 Meadows, and those bordering Broad Cove and the tidal portion 

 of Weymouth Back River between the railroad and the barrier 

 due to the jutting out from either shore of a kame-like ridge 

 of modified drift. Several of the smaller mai'shes, as previously 

 stated, were reclaimed during the early settlement of the 

 country by means of dikes. A large part of Hingham Harbor 

 has advanced, in the process of silting up, to the eel-grass stage. 

 Weymouth Back River is much less advanced simply because 

 it is a long narrow basin and the tidal-scour is more concen- 

 trated and efficient. 



Besides the growth of peat on the salt marshes, there are 

 extensive deposits in the fresh-water swamps and meadows ; 



