34 GEOLOGICAL AGE AND FORMATION. 



left, and there is every, indication that the whole island 

 will soon be covered by the marsh. 



The swamps of white cedar, adjoining the marshes, are 

 continually encroached upon by the tide ; the timber on 

 the borders is gradually being killed by the salt water ; and 

 hundreds of acres are to be seen about Dennisville all 

 dotted over by cedar stumps, which are still standing 

 where they ' grew, though the salt grass has long since 

 taken the place of the living timber. The soft and spongy 

 nature of the cedar swamp-bottoms would lead one to sup- 

 pose that the mud, with the load upon it, was gradually 

 going down, were it not for the fact that these bottoms are 

 found far below tide-level, and the muck of which they con- 

 sist, extending down to the gravel. The following section, 

 from examinations made in company with Dr. Maurice 

 Beesley, shows the extent, and some of the effects of this 

 settling. 



The timber and earth of the swamp, it will be seen, ex- 

 tend quite down to the hard ground, which is eleven feet 

 under the surface of the marsh. In some trials which were 

 made in the thoroughfare between Dennis and Goshen Creeks, 

 the cedar swamp earth was found at least seventeen feet 

 below the level of the marsh ; and some cedar stumps of 

 large size are known to be in the bed of Dennis Creek, 

 which are covered by seven feet of water at low tide. The 

 appearance of these last-mentioned, indicates that they are 

 in the spot where they grew. 



Some years since, an outlet was needed from a number 

 of tide-ponds near East Creek, into Dennis Creek. For this 

 purpose a ditch, ten feet wide and three feet deep, was dug 



