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Book 11. Chap. II. Beds between (he
at the bottom of Geer’s Wood , and on the skirts of Filmoor.(Morn. Chron. Dec. 1810. G. Notes.)
Silicified wood occurs in it at Aspley, Crawley, and otherplaces in Bedfordshire ; and jet is said to have been worked inthe parish of Wotton on the borders of Surrey and Sussex.(G. Notes.)
Coaly matter occurs in the parishes of Crawley and Warp-lesdon in Surrey ; and at Ftimwell the sand contains car-bonaceous matter and a thin bed of vegetable. (G. Notes.)
The beds of fullers’ earth which occasionally alternate inthis formation, have been extensively worked in Bedfordshire .An account of them is given in the Philosophical Transactions for 1723, by Mr. llolloway ; as this memoir is very short, pos-sesses considerable merit, well illustrates the disposition of thebeds of this formation iu that part of their course, and is more-over highly interesting as a very early specimen of accurategeological observation, it is reprinted in the note below.*
* An account of the pits for Fullers* earth in Bedfordshire ; in a letterfrom the Rev. Mr. B. Holloway, F.L S. to Dr. Woodward, &c. From theTransactions of the Royal Society , vol. xxxii. p. 419.
Bedford, 6th July, 1723.
tc t went a few days ago to the Fullers’ earth pits at Wavendon nearWoburn, where there are several pits now open; but, as the men wereonly at work in one, and I understood the earth was disposed in much thesame manner in all, I did not trouble myself to go down into more thanthat wherein they were digging; in which I found things disposed thus.
From the surface, for about six yards depth, there are several layers ofsands, 2 II reddish, but some lighter coloured than others, under whichthere is a thin stratum of red sandstone, which they break through; andthen for the depth of about seven or eight yards more, you have sandagain, and after that come to fullers’ earth; the upper layer of which,being about a foot deep, they call cleJge\ and this is by the diggers thrownby as useless, by reason of its great mixture with the neighbouring sand,which covers, and has insinuated itself among it; afterwards they dig upthe earth for use to the depth of about eight feet more, the matter whereofis distinguished into several layers, there being commonly a foot and ahalf between one horizontal fissure and another. Of these layers of fullers*earth, the upper half, where the earth breaks itself, is tinged red, as itseems by the running of water from the sandy strata above, and this partthey call the crop , betwixt which, and the cledge above mentioned, is athin layer of matter not an inch in depth, in taste, colour and consistencynot unlike to Terra Japonica. The lower half of the layers of fullers’ earth,they call ivall-earth; this is untinged with the red above mentioned, andsesms to be the more pure and fitter for fulling; and underneath all is astratum of white rough stone, of about two feet thick, which, if they digthrough, as they very seldom do, they find sand again, and then is an endof their works.
One thing is observable in the site of this earth, which is, that it seemsto have every where a pretty horizontal level, because they say that whenthe sand ridges at the surface are higher, the fullers* earth lies proportion-ately deeper.