Soils and subsoils from a sanitary point of view : with especial reference to London and its neighbourhood / by Horace B. Woodward.
- Horace Bolingbroke Woodward
- Date:
- 1897
Licence: Public Domain Mark
Credit: Soils and subsoils from a sanitary point of view : with especial reference to London and its neighbourhood / by Horace B. Woodward. Source: Wellcome Collection.
Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.
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![pleasantly situated and picturesque, and only in a few localities where the gravel descends to lower grounds bordering the Colne valley would the sites be liable to damp. As the water in the underlying Chalk is largely drawn upon for drinking-purposes, it is most desirable that the sanitary arrangements in dwelling- houses be so constructed that no pollution of underground water is possible. Here and there patches of gravel occur on the Bagshot Sands, as in Essex and Surrey, and the localities are noted in the descriptions of these sandy areas. Blackheath Beds.—These are composed of gravel, made up almost entirely of flint-pebbles in a sandy matrix. In thickness they vary from about 10 to 50 feet or more. Their distribution is restricted. Appearing at the surface at Croydon they extend over a considerable tract betAveen Addington and Beckenhain; they occur at Brojuley, Hayes Common, Keston, Chislehurst, and Eltham, and again at Bexley, East Wickliam, Charlton, and Blackheath. Outlying patches lie south of Caterham and at Worms Heath near Chels] liam. Everywhere the soil above these deposits may be regarded as naturally dry and healthy, and the district is usually picturesque, and admirably adapted for residences. The situation of these gravel-beds being more elevated than that of the valley gravels, they have in tnis respect a decided advantage. In short they may be considered to afford sites as good generally, from a sanitary point of view, as those on the large areas of the Bagshot Beds, and perhaps of the higher gravels on the Chalk of Hertfordshire and Buckmghamshire. Bagshot Beds.—These strata, which take their name from Bagshot Heath in Surrey, are most largely composed of sands, with occasional thin seams of white pipeclay and pebbly layers. They contain a central clayey or loamy division which supports pools of water, such as the Fleet Pond, north of Aldershot. To the north-east of London, small tracts of Lower Bagshot sands form the hilly ground at High Beech, near Loughton, there covered irregularly by gravel. Between High Beech, Loughton, and Epping, the ground is mostly of a light and loamy nature, with here and there beds of sand and sprinklings of gravel. The fact is that the London Clay, which lies below, passes up into the Bagshot Sands by alternations of sand ancl clay. These mixed soils occur also over the area east of Epping, near Theydon Bois, by Gaynes and Ongar Parks, and elsewhere. More definite areas of Bagshot Sand are to be found in many parts of south-eastern Essex, at Hadleigh and Rayleigh, at Billericay, Stock, and near Ingatestone, at Kelvedon Hatch, Brentwood, Warley, and Southweald, at Langdon HiU, and a^ain at Crabtree Hill, near Lambourn. Here the sands are overlain in places by pebble-gravel. Ao-ain, small areas of Bagshot Sand are observable at Higligate, Hampstead, and Harrow, where also towards the base of the sand, pebbly layers with ironstone occur. The junction with the underlying London Clay is at these localities also marked by alternations of sand and clay, as recently shown in excavations](https://iiif.wellcomecollection.org/image/b21465484_0024.jp2/full/800%2C/0/default.jpg)
