400 
collected from their salt-pans, con- 
nected with drains and ditches that 
run into the sea, and which are cover- 
ed with sail-cloths. 
—<p_— 
To the Editor of the Monthly Magazine. 
SIR, 
R. Farey says, ‘it is not true, 
that beneath the line or level of 
high water, fresh water can be obtained 
by digging on the sandy shore, except- 
ing only in those cases or spots where 
large quantities of land-water (derived 
in all instances from previous rains, 
snows, or dews,) are passing through 
such sand in its way to the ocean, as its 
lowest vent, or place of discharge: in 
all other cases a hole sunk in the sea- 
sand would be wholly, or partially, 
filled with salt-water left in such sand 
by the retiring of the tide.” And, ac- 
cording to Bacon, (SylyaSylv.) ‘* Czesar 
thought that all sea-sands had natural 
springs of fresh water.” ‘‘ But,” says 
Bacon, ‘itis plain that it is sea-water, 
because the pit filleth according to the 
measure of the tide.” ‘* And,” adds 
Capt. Layman, “ the fresh water (in the 
pits) ebbed and flowed with the tide.” 
Now, supposing Bacon tohave beena 
mere theorist, which, from his confident 
manner of describing this phenomenon, 
and his known assiduity in attempting 
to penetrate the secrets of nature, 
there is no reason to believe, yet have 
we here. the positive, matter-of-fact 
testimony of Captain Layman, that the 
water im the pits ebbed and flowed 
with the tide. 
Therefore, notwithstanding the in- 
genious and scientific arguments of 
Mr. Farey, we ought to patise before 
we subscribe to his opinion, that 
“Capt. L. essentially errs in stating 
the principles on which he attempts to 
account for the phenomenon, and as to 
the general applicability of his me- 
thod.” For its ebbing and flowing with 
the tide, if not conclusive, is an impor- 
tant fact towards proving, that the 
fresh water thus obtained is sea-water 
purified by percolation through the 
sand. 
Fceling an interest in this question, 
from its evident general utility, I have 
made some inquiries among my nau- 
tical friends, with a view to ascertain 
both the truth and the cause of this 
phenomenon. Several captains” of 
ships with whom I am acquainted, 
and who spent the greater part of their 
lives at sea, have told me that the 
4 
Mr. Fitch in Answer to Mr. Farey. 
u 
[Dee. tf» 
practice is very oommon; that, or 
various parts of the coast of Africa, 
and in other parts of the world, they 
have frequently obtained water by this 
method ; but, lam bound in candour to 
add, that they all agreed that the wa- 
ter so obtained had a brackish taste, 
and was not so good for many purposes 
as river-water. This, however, which 
appears to be an additional proof that 
the water in the pits is sea-water, 
freshened by percolation through the 
sand, was probably occasioned by the 
shallowness of their pits; for, their 
usual method ‘of making the experi- 
ment, I find, was to dig a hole in the 
sand, and sink therein a tub, to keep 
up the sides. A trial upon this scale 
can hardly be said to produce the de- 
sired effect. Bacon says, ‘ Dig a pit 
upon the sea-shore, somewhat above 
the high-water mark, and sink it as 
deep as the low-water mark, and as the 
tide cometh in, it will fill with water 
fresh and potable.” There is a wide 
difference between sinking a tub in a 
hole in the sand, and digging a pit of 
the depth, and consequent capacity, 
described by Bacon. ‘There is another 
point wherein there is a remarkable 
coincidence between the obseryations 
of Bacon and Capt. Layman. ‘The 
latter tells us, that the water from the 
pits was “more pure and free from 
earthy salts than river-water.” And 
the former says, “ all earth hath in it 
a kind of nitrous salt, from which sand 
is more free; and, besides, earth doth 
not strain the water so finely as sand.” 
Will Capt. Layman have the good- 
ness to state whether he dug his pits 
above the high water-mark, and to 
what depth? ‘J. Fircr. 
Stepney, Oct. 3. ~ 
—_ = 
To the Editor of the Monthly Magazine. 
SIR, 
‘& MONGST the many valuable and 
practical hints for social im- 
provements, which your pages have 
successively contained, you gave in p. 
106 of your September number, the 
letter of Mr. James Gilbertson, of 
Hertford, stating the mode in which 
his tallow-melting house had been ren- 
dered innoxious to his neighbours, 
who often previously had complained 
bitterly thereof; and, very properly, 
the same subject was revived in p. 
284 of your October number. 
I am happy, therefore, as a con- 
stant reader of your work fromits com- 
mencement, 
—— 
