PHYSICAL AND GEOLOGICAL DESCEIPTION. 21 



hillocks rather than in extended ridges ; and the streams, 

 which in some countries indicate a general direction for 

 the valleys and ridges, are here short. They rise in the 

 swamps and higher flat grounds in the central part of 

 the county, and run directly towards the ocean or Bay. 

 The only valley of much length is that of the Great Cedar 

 Swamp, which extends from Delaware Bay to Great Egg 

 Harbor, a distance of fifteen miles. Its direction is north- 

 east and southwest. In that part of the county, between 

 this valley and the Cumberland line, the ridges and 

 streams tend to a northeast and southwest direction more 

 than to any other ; but the difference is not a very marked 

 one. 



§ The soil and subsoil of the upland is generally a sandy 

 loam; in some places so light as to be called a sandy 

 soil, and in others with clay enough to make it a loam. 

 Gravel is found in all parts of the county, though very 

 irregularly deposited. It is coarser and more abundant in 

 the northern and northwestern parts. At North Dennis- 

 ville, at Petersburg, and on the intervening ridges, all of 

 which lie on the northwest margin of the Great Cedar 

 Swamp, the gravel is very coarse, and forms a large con- 

 stituent of the soil. In the wells, which are generally 

 from eight to twenty feet deep, the materials passed 

 through are similar to those upon the surface, consisting 

 of sand and gravel, with an occasional layer of compact 

 clayey loam. At Cape Island there is a bluflf bank about 

 twelve feet high, and several hundred yards long, which 

 gives a short section of the material which forms the 

 Island, It is a fine, loamy sand, with some gravel, similar 



