Note d — BOOK III.

It is not only agreeable to Reason, but I am told by Persons conversant in digging of Wells throughout this County of Essex, where I live, that the surest Beds in which they find Water, are Gravel, and a coarse, dark coloured Sand; which Beds seldom fail to yield Plenty of sweet Water: But for Clay, they never find Water therein, if it be a strong, stiff Clay; but if it be lax and sandy, sometimes Springs are found in it; yet so weak, that they will scarcely serve the Uses of the smallest Family. And sometimes they meet with those Beds lying next, under a loose, black Mould, (which, by their Description, I judged to be a sort of oazy, or to have the Resemblance of an ancient, rushy Ground,) and in that Case the Water is always naught, and stinks. And lastly, Another sort of Bed they find in Essex, in the clayie-Lands, particularly that part called the Rodings, which yields Plenty of sweet Water, and that is a Bed of white Earth, as though made of Chalk and white Sand. This they find, after they have dug through forty, or more Feet of Clay; and it is so tender and moist, that it will not lie upon the Spade, but they are forced to throw it into their Bucket with their Hands, or with Bowls; but when it comes up into the Air, it soon becomes an hard white Stone.

Thus much for the Variety of Beds wherein the Waters are found. That it is in these Beds only or chiefly the Springs run, is farther manifest from the forcible Eruption of the Waters sometimes out of those watery Beds. Of which see Chap. 4. Note (k). This Eruption shews, that the Waters come from some Eminence or other, lying at a Distance, and being closely pent up within the watery Stratum, by the clayie Strata, the Waters with force mount up, when the Strata above are opened.