VOL. IV.] PHILOSOPHICAL TRANSACTIONS. 3Q7 



and various, it is probable, that hyperbolical glasses must be derived from these 

 principles, or none. 



Some Inquiries concerning the Salt Springs and the Way of Salt-mahing 

 at Nantivich in Cheshire, answered by William Jackson, M. D. 

 N" 53, p, 1060. 



1. What is the depth of the salt springs ? — ^The depths are various, in some 

 places not above three or four yards; at Nantwich, the pit is full seven yards from 

 the footing about the pit; which is guessed to be the natural height of the 

 ground, though the bank be six feet higher, accidentally raised by accumulated 

 rubbish or walling as they call it. In other places the springs lie much shallower; 

 for in two places within our township the springs break up so in the meadows, 

 as to fret away not only the grass, but part of the earth which lies like a breach 

 at least half a foot or more lower than the turf of the meadow, and has a salt 

 liquor, oosing as it were out of the mud, but very gently, 



2. What kind of country it is where the springs are, whether hilly, &c. ; and 

 what plants grow near them ? — Generally a low ground, yet very full of collicular 

 eminences, and various risings, to distinguish it from being all meadow. We 

 have also a peculiar sort of ground in this county and some adjacent parts, 

 which we call mosses, they are a kind of moorish boggy ground, very stringy 

 and fat : which serves us very well for turfs, cut out like great bricks and dried 

 in the sun. In these mosses is found much of that wood we call fir- wood, 

 which serves the country people for candles, fuel, and sometimes for small 

 timber uses. They generally seem to be places undermined by some sub- 

 terraneous streams ; or by the dissolution of some matter that made them equal 

 with the rest of the ground formerly : In which conjecture I am confirmed by 

 this, that near a place of my Lord Cholmondeley's, called Bilkely, about nine 

 or ten years since, not far from one of these mosses, without any earthquake, 

 a piece of ground about 30 yards over fell in, and drew in great oaks growing 

 on it, which hung first with part of their heads out, afterwards suddenly sunk 

 down into the ground, so as to become invisible : Out of which pit they drew 

 brine with a pitcher tied to a cart-rope, but could then find no bottom with the 

 ropes they had there: The pit has been since filled up with water, and now 

 does not taste salt, but a little brackish, a very small rindlet passing, through it. 

 The nearest salt-springs to this place are at Dartwich about three miles from it. 

 We have some hills, but not large, near our springs ; which generally lie all 

 along the river Weever, as Hankillow, Hatherton, Osterson, Bartherton; Nant- 

 wich, Weever, Leftwich, Northwich; yet there is an appearance of the same 



