XVI INTRODUCTION. 



junction witli the underlying clay, ' liave given tlieir names to the 

 thickly-housed districts that were the means of their destruction — 

 Clerkenwell, Bagnigge wells, and Coldbath fields' (p. 90). The 

 boundary of the gravel of the Lea Valley is ' in great part doubtful/ 

 but it passes from Stoke Newington, west of Tottenham, Edmonton, 

 and Enfield, to Waltham Cross, and ' from Enfield to Clay Hill it fol- 

 lows ' the line ' of the new river on its west ' (p. 92). South-east of 

 Southgate there is gravel which may be either high-level or a higher 

 terrace of the Lea gravel (p. 71). The shallow wells of London get 

 their water from the gravel, and from it the springs, besides those 

 already mentioned, formerly numerous in Loudon, especially at Isling- 

 ton and its neighbourhood, have been thrown out along the valleys. 

 They now mostly supply pumps or pass into sewers. Such were Holy 

 Well, Skinner's Well, Dame Annis de Cleare, Perillous (or Peer- 

 less) Pond. Some of them, as Sbadwell (S. Chad's well), had medi- 

 cinal qualities. Bagnigge Wells and Islington Spa, or new Tonbridge 

 Wells, were cathartic and chalybeate.* 



The brick earth overlies the gravel, but is not always present ; it is 

 a brown sandy clay or loam, very valuable not only for brick making, 

 but also for the fine soil it affords the market gardener. Mr. Prest- 

 wich regards the brick earth as a deposit from flood waters. For a 

 detailed accoimt of the relations of the brick earth to the gravel, and 

 the exact limits of these deposits, reference must be made to Mr. 

 Whitaker's Mejnoir. In many places in the south-west of the county, 

 the appearance of the surface has been much altered by the extensive 

 working of the brick earth. At West Drayton and thence to Southall 

 there is a great sheet of it, giving rise to many and extensive brick- 

 yards (p. 86) ; near Drayton and elsewhere it has been quite worked 

 out, and the gravel laid bare. Brick earth, forming the middle terrace, 

 extends between East Acton and Netting Hill, from Wormwood 

 Scrubs to the Thames, and is less sandy and not unlike London clay. 

 Near Highbury the brick earth is very thick, nearly 30 feet of it 

 having been found. At Newington it has been worked away, and the 

 houses built of bricks made from it rest on the gravel (p. 89). 



' In the British Museum there is a flint weapon of the spear-headed 

 form, which we are told was found with an elephant's tooth at Black 

 Mary's, near Gray's Inn Lane. In a letter dated 1715, printed in 

 Hearne's edition of Leland's Collectanea, vol. i. p. 73, it is stated 

 to have been found, in the presence of Mr. Conyers, with the skeleton 



* other springs were on the London clay, e.^.,IIighwood Hill and Kilburn (cathartic), 

 St. Pancras and Acton. 



