Topographical Features of the JS'ew Haven region. 1 09 



by the commencement of the new wharf ). In the eastern corner of 

 this basin, after crossing this mud-channel, a hard impenetrable bot- 

 tom was found at 18 to 20 fathoms. 



e. In driving piles for the bridge of the New York Railroad, across 

 West liivei', toward its mouth, the hard-pan was found at a depth of 

 35 to 40 feet ; and for the Derby Railroad crossing, a little farther 

 north, at 25 to 30 feet ; in one case 40 feet. In these, and other cases, 

 the layer was not so thick but that the piles could be driven through 

 it, and when thus passed, they descended many yards before finding 

 good bottom again. 



f. The piles for the Air-line railroad, over the Quinnipiac meadows, 

 found a hard bottom at a maximum depth of 40 feet. 



g. Last year piles were driven in the West Creek region, near the 

 southeast corner of Congress Avenue and Oak street, which descended 

 20 feet before striking a hard bottom. 



h. An artesian well sunk by the Messrs. Trowbridge on Long Wharf, 

 about 350 yards outside of the old coast line, found a supply of fresh 

 water, but slightly brackish, in a layer of gravelly hard-pan at a depth 

 of 20 feet, or 14 feet below mean-tide level. 



i. Another artesian well, on the same wharf, but 400 yards farther 

 from the old coast line, made by Mr. Aaron Kilburn, under the direc- 

 tion of Capt. S. J. Clark, found water at a depth of 56 feet. The 

 boring (6 inches in diameter) passed through 28 feet of mud; and 

 then about the same thickness of earth resembling the ordinary sand 

 beds of the plain, without any large stones ; and the water at first 

 rose to a height of 6 feet above the top of the wharf. Allowing for 

 the height of the wharf, and the penetration of the hard-pan to a 

 depth of 3 feet, the layer here lies 45 to 48 feet below mean-tide level. 

 The depth consequently was very nearly the same with that ascer- 

 tained by pile-driving at the end of the wharf. 



j. At the Staples Block Factory, on Long Wharf, just north of the 

 Messrs. Trowbridge, an artesian well was sunk by Mr, Kilburn to a 

 depth of 45 feet below the surface of the wharf, or 39 feet below 

 mean-tide level, and perfectly good fresh water obtained. The boring 

 passed through 32 feet to the bottom of the mud, then through sand 

 and gravel like that of the New Haven plain, in the course of which 

 there were 2 feet of hard blue clay, a very hard hard-pan, as Mr. Kil- 

 burn describes it. 



k. In another artesian boring, made by Mr. Kilburn, at the depot of 

 the New York and New Haven railroad, east of the commencement of 

 Long Wharf, good water, entirely free from brackishness, was obtained 



