WELL. 



diately over, the fpring burft up with fuch force, and in 

 fuch abundance, that the workmen immediately made the 

 (ignal to be drawn up. Within the firft four hours after its 

 difcovery, the water rofe to the height of eighty feet, m the 

 next twenty-four hours about forty feet more ; after which 

 it continued to rife gradually for the next fortnight, till it 

 reached its prefent level, which is only four feet from the 

 furface of the earth, the depth of the water being now only 

 one hundred and fixty feet. 



Depths of ftrata paffed through : 



1 Clay 



2 Stone ... 



3 Clay - - - 



4 Sand ... 



5 Clay - - - 



Feet. 



6o 



I 

 29 

 23 

 51 



164 



At Mr. Monday's brewery at Chelfea, a well was dug 

 about the year 1793, to the depth of three hundred and 

 ninety-four feet, within twenty or thirty feet of the edge of 

 the river, moftly through a blue clay or marl. At the 

 depth of near fifty feet, a quantity of loofe coal, twelve 

 inches in thicknefs, was difcovered ; and a httle fand and 

 gravel were found about the fame depth. The well-digger 

 ufually bored about ten, fifteen, or twenty feet at a time 

 lower than his work, as he went on ; and on the laft boring, 

 when the rod was about fifteen feet below the bottom of the 

 well, the man felt, as the firft fignal of water, a rolling 

 motion, fomething like the gentle motion of a coach palTing 

 over pavement. Upon his continuing to bore, the water 

 prefently puflied its way by the fide of the auger with great 

 force, fcarcely allowing him time to withdraw the borer, 

 put that and his other tools into the bucket, and be drawn 

 up to the top of the well. The water foon rofe to the 

 height of two hundred feet. 



In 1794, a well was funk at Norland-houfe, for Mr. 

 Vuliamy, a little on the road towards the town of Ux- 

 bridge, to the depth of two hundred and thirty-fix feet, 

 and then a hole of five inches and a quarter was bored down, 

 and a copper pipe of the fame diameter as the borer, was 

 driven down to the additional depth of twenty-four feet 

 into a ftratum of fand filled with water ; when a mixture of 

 fand and water inftantly rufhed upwards through the 

 aperture of the pipe in fuch abundance, as to rife one 

 hundred and twenty-four feet, that is, one hundred feet in 

 the well part, and twenty-four in the pipe, in the courfe of 

 eleven minutes, and one hundred and nineteen feet more in 

 one hour and nine minutes ; or on the whole it rofe two 

 hundred and forty-three feet in one hour and twenty 

 minutes. A found line was then let down, which difco- 

 vered that fand had rofe in fuch quantity as to fill the well 

 to the height of ninety-fix feet. This was under the ne- 

 ceffity of being repeatedly dug out, by which the fand was 

 ultimately reduced fo confiderably as to permit the water to 

 rife through it more and more freely, until it flowed over 

 the top of the well at the rate of forty-fix gallons in the 

 minute. There is ftill, however, a great body of fand in 

 the welljjthrough which the water filters by afcent, which 

 13 excellently calculated for freeing it from every fort of im- 

 purity. If a greater fupply of water at this well were ne- 

 ceffary for the valuable purpofe of turning machinery of 

 any fort, or for any other fuch ufe, it might certainly, it is 

 faid, be obtained after the rate of feveral hundred gallons in 

 the minute, by continuing to clear out the fand until the 



obftruftion it affords fhould become of little confequence ; 

 but, in this cafe, the quality of its water is of more im- 

 portance than the quantity. The water, in this inftance, is 

 now had in a very high ftate of purity, as the originally ex- 

 cellent water, rendered fo by flowing in a ftratum or body 

 of clear fand, is further purified and improved by filtrating 

 by afcent through many feet in thicknefs of the fame 

 material. 



Other circumftances have occurred in digging and form- 

 ing wells in different fituations. It is ftated in the Rural 

 Eflays, that in finking a well at Sheernefs, near the mouth 

 of the river Thames, fometime fince, fome extraordinary 

 phenomena or appearances occurred, many of which were 

 deemed, by different perfons, rather of a wonderful kind. 

 They were thefe : that fort is placed upon a neck of land, 

 very httle elevated above the furface of the fea. In dig- 

 ging the well, they paffed firft through a bed that con- 

 fifted wholly of fand to the depth of thirty feet, the whole 

 of the water found in which was of a fait tafte, when at that 

 depth they difcovered a fpring of ya/Z-water, which, not being 

 irrefiftibly abundant, they found themfelves enabled to wall 

 out ; which being accompliflied, they then funk further, 

 through a bed of clay for fome fathoms more. They here 

 found another fpring of falt-water, as before ; which having 

 walled out in a fimilar manner, they continued to dig 

 through the fame bed of clay, for three hundred feet more ; 

 at the bottom of which they found a bed of gravel, from 

 which iffued a copious ftream of frefti water, which foon 

 filled the well within five feet of the top ; at which height 

 nearly it has ever fince remained. 



Extraordinary as thefe circumftances may appear, they 

 arc perfeftly explicable on the principles and appearances 

 which take place in boring and lapping fprings. The frefh 

 water, in this cafe, being confined and pent up at a very 

 great depth in the earth, by impervious beds of materials, 

 when the gravel or porous ftratum that contained the water 

 was funk down into it, was forced up and rofe, of courfe, to 

 the height of the internal fource or refervoir from which the 

 water originally came in the diftant high ground. If the 

 fpring in this inftance fhould afford more water than is taken 

 from the well, it will continue always about the above 

 height ; fo that the water can only fink in the top of the 

 well, when more is drawn from it than the fpring can fup- 

 ply in a given time. See Tapping Springs. 



The fprings of falt-water in this cafe are capable of being 

 explained on the fuppofition of fiffures or openings having 

 been formed by the working of fome fort of animal, or other 

 unknown caufe, fo as to have penetrated the bed of clay, 

 from the edge next the fea to fome diftance, as far inward, 

 at leaft, as the opening of the well ; through which, of ne- 

 ceffity, falt-water would flow into the well as foon as it was 

 opened. See Philoft)phical Tranfaftions, vol. 74. 



Another inftance of a fomewhat fimilar kind, though lefs 

 complicated, as being divefted of the circumftance of the 

 falt-water, is mentioned to have taken place at Derby, 

 under the direftion of a late eminent phyfician and philofo- 

 pher. A well was funk in that place, which lies in a 

 bottom, furrounded by many different hills ; in which, after 

 digging through a bed of clay for fome coiifiderable depth, 

 an abundant fpring of frefti water was founil, which, as in 

 moft cafes of this nature, rufhed up with great impetuofity, 

 and foon filled the well to the top, where it flowed over in a 

 pretty full ftream. This was ini1:antly feen, and conceiving 

 that it probably defcended through fome narrow fubter- 

 raneous paffage, from a height greater than that of the 

 houfes of the town, readily imagined that if the fides of the 

 well could be railed to a fuiBcient height, making them at 



the 



