Figs. 243-245.
Well at Highbury.

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Highbury, Middlesex.—Well at the residence of H. Rydon, Esq., New Park. [Figs. 243 to 245]. The shaft is 4 feet 6 inches diameter, and 136 feet deep, steined with 9-inch work set in cement. The bore was commenced with a 12-inch hole, but the character of the ground was such that the successive reductions in size, shown in the enlarged section of the lining tubes, [Fig. 245], had to be made. When in the chalk the bore was continued some 48 feet unlined. The strata passed were;—

Gravel 3feet.
London Clay, 111 feet;—
Blue Clay110 „
Claystone 1 „
Reading and Thanet Sand, 85 feet;—
Mottled Clay 25 „
Coloured Sand 60 „
To Chalk199 „
Chalk 50 „
Total249 „

Kentish Town.—This well was sunk under the supposition that as the outcrop of the subcretaceous formations was continuous around the margin of the cretaceous basin surrounding and underlying the London tertiaries, except at the eastern border, those subcretaceous formations would be found under London, just as they actually were at Paris. This proved to be the case until the gault was passed, when a series of sandstones and clays was encountered, occupying the place of the lower greensand, but evidently of older geological character, and having many of the features of the new red sandstone.

Figs. 246, 247.
Boring at Kentish Town, London.

The surface of the ground, [Fig. 246], is 174 feet above Thames high-water mark. There is a shaft for 539 feet; the remainder being bored. The following detailed account of the strata is due to Prestwich.