166 
Essex Well-Seetions. 
Thickness. Depth. 
FT. IN. FT. IN. 
Chalk : marly from 308 to 355 ft. deep, with 
flint water-bearing veins at 360 ft., greyish 
and firm at 367, hard and white at 426, hard 
at 440, soft with flints and water-veins at 
460, darker and harder at 475, flint-veins full 
of water at 502, grey and waterless at 5064, 
white with flints and water at 521, grey with¬ 
out water at 529, soft with cavities, flint-veins 
further apart but full of water, at 536, hard 
and dark 540—545, softer and whiter at 550, 
white and marly 566—572 . 303 6 ... 572 0 
Tilbury Fort.— (Old Well). 
1 Gentleman’s Magazine,’ vol. lxviii., p. 565 (1798). 
Dug 48 feet; tlie rest bored. 
Dry earth [made ground ?], thin. 
Clayey beds, with leaves and branches of trees, 
about 48 ft. 
Quicksand. 
Stiff marl, ? 30 ft. 
Chalk-stones found at a depth of about 80 ft. 
Tilbury Fort .—(Newer Well). 1849. 
Communicated by Col. E. M. Grain, R.E. W ith further 
information from Lieut.-Col. Brine, B.E. 
Shaft and cylinders, 31 feet; the rest bored. 
Water, March 22nd, 1849, good; April 19tli, impure ; 
May 25tli, good; since become quite unfit for domestic 
purposes (although pipes were carried to a depth of 490 feet). 
TVFnrlp crvmmrl 
Thickness. 
. 3 ... 
Depth. 
o 
O 
(Strong mud or blue clay ... 
114 ... 
144 
Peat with clay. 
54 ... 
20 
[Alluvium, 
41 ft,] 
Clay . 
3 ... 
23 
Dark peat. 
8 ... 
31 
Stiff clay . 
8 ... 
39 
(Dark peat . 
5 ... 
44 
(Dark sharp sand . 
7 ... 
51 
[River Drift, 
Sharp sand and gravel . 
4 ... 
55 
234 ft.] 
Light [-coloured] sharp sand 
L and gravel . 
124 ... 
67^ 
Chalk . 
517 ... 
5844 
