22 
three hundred feet, being there futh- 
ciently open, by means of its numerous 
eraeks or fiflures, to Tet the rain water 
fsak frecly down, almoait, or quite to 
the level of the fea. Mr. Smith, has 
to me and numerous others, demou- 
frrated in the exercife of his proteffion, 
and be will fhortly publifl an unportant 
work on the fubject, that every liratum, 
whether of clay, fand, chalk, ttone, we. 
which we meet with m finking a well, 
or pit, however decp, forms part of an 
extended inclining plane, of nearly equal 
thicknefs throvghout; which, at a great- 
er or lefs diflanee from the well, armves 
at, aud crops or baflets out upon the 
farface, generally for a long difiance 
togethcr, and that all, or moft of the 
porous firata, as fand, or open rock, are 
thus at their our-crops fupphed with 
water, which percolates, or foaks down 
them, often to complete faturation, 
The decp wells in London and its vi- 
emity, furnifh us with inftances.of this 
fas kind of fprings; many of thefe wells 
frit pafs through the gravel and other 
alluvial matters, containing a fmall {pring 
of the firft kind, before they euter a 
thick firatum of clay; a few feet within 
this clay, layers of thofe Gngular nodules, 
eslled Zudus Helnionti, are frequently 
found, and in ‘fome iufiances the fame 
produces a fimall fpring, much impreg- 
nated with mineral‘qualitigs ; after pro- 
ceeding a great way further m the clay, 
a ftratum of fand is met with, and 
which fand fometimes produces water, 
but in no great quantities, and often 
unfit for culinary purposes: the two 
fprings, lait menticncd, are ftopped or 
walled out by the well-digger, a pro- 
eefs which [inait take fone other op- 
portunity of explaining, and either the 
finking of the well, or the 
a large angur-hole, proceeds further 
throuch the clay unt a thick ftratum 
of loofe fand is reached, cften at three 
hundred feet deep, fo perfectly farurated 
and charged with water as to produce 
the efeéts, defcribed by, Mr. Vulhainy, 
near A¢ton, and mentioned by Aquarius 
at p. 433. | 
The rife of water in dcep wells near 
London, 1s always very contiderabie and 
Hts quantity great, aiter the thick fend 
fratum is reached; m fore wells in low 
fiiuations, #t attually flows over above 
the cround, as in Richmond ‘Fown, in 
Thames Street, London, and other 
places, Befides Mr. Vulliamy’s ; and 
this would be the cafe more ceneraily, 
or perbaps, univerfaly im fuch firuations, 
‘On Hells and Springs. 
boring of 
[April 1. 
if the water did not efcape through the 
grayel and {and on the top of the clay; 
an inftance of which, I have obferved in 
{ome modern wells, on the fouth fide of 
the village of Eaft Sheen. 
The out crop of the thick ftratum of 
fand fupplying the deep wells near Lon-, 
don, particularly thole north of the 
river, may be traced through the pa- 
rifhes of Seuth Mims, Ridge, Buthey, 
Ritclit, and other places about fitteen 
or fixteen miles from London, ‘whofe 
confiderable elevation above the level 
of the metropolis fully accounts for the 
force with which the water is there fent, 
in this lower fand ftratum, and in the 
chalk on which it refts. The village 
of Rifclif furnilhes a curioys. example 
of the general ignorance or want of per- 
‘feverance in well-finking in thofe parts ; 
‘ach wells as they have Gf my mtorma- 
tion on the fpot, when tracing the out- 
crop of the above fand, be correct) 
reaching no further than the firft fand, 
and producing a bad and unwholefome. 
water, which might ealily be walled out, 
and the remarkably good water procured 
in plenty in their town, which they now 
fetch in drags a diftance of halt a mile 
from its accidental vent in the mea- 
dows. 
Our newly acquired knowledge of 
the ttratifcation, while it points out 
the pollibility of finding plenty of water 
in apy place, and furnithes data for guefi=, 
ing atits quality, and calculating nearly | 
the expence at which it may be got; 
by making known all the matters com- 
pofing the fouth and cafiern parts of 
‘this ifland, has rendered the expecta- 
tions vain, of digging coals in all thefe 
parts, notwithfianding the confident af- 
fertions in your Magazine to the con- 
trary, by certain fpeculators in Suifex, 
fee vol. xxi, p. 584, aid vol. xxi. p. 94. 
I might have iwentioned above, that 
every coufiderable brewer in .London 
has now a deep well, and raifes the fand 
or chalk fprmg-water, above-mentioned, 
for ufe m brewing his porter, tle pe- 
cular properties of which beverage 
were herctofore afcmbed by many toe 
the nfe of the Thames water. 
The vale of the Thames, is not. the 
. only ftuation where overflowing wells 
might be had; almoft any low tituation 
might faurnith them, by proper manages 
ment, and fometimes a confiant rill of 
water, of no inconfiderable ufe, might thus 
be obtained, as I have myfelf witefled, ® | 
Weftminfler, Your’s, &c. \ 
is February, 1807, “Joun mai 2 
‘OP 
