1822: ] 
gest the propriety, of tracing out, bya 
pretty accurate levelling, and _ the 
mapping, of a level line on the surface, 
(such as a canal without any locks 
might oceupy,) from the outlet near 
Maidenhead, eastward, to intersect 
the Colne river; ascertaining, at the 
same time, any difference of level and 
distance there may be, between this 
point of intersection and the lowest 
place of outlet for the chalk-water 
in the vale of the Coln, near Uxbridge. 
In like manner, should the same 
level line be traced and mapped, 
south-eastward from Maidenhead, to 
intersect the Wey river; comparing 
the same, as to level and distance, 
with the lowest chalk-water outlet in 
that valley ; and soon, eastward, with 
respect to the Mole and the Wandle 
rivers, and their respective lowest 
chalk-water outlets. 
In this, asin almost all other classes 
of natural phenomena, some anoma- 
lies occur, which complicate the mat- 
ter, and require the aid of science and 
research, for their elucidation: here, 
for instance, the Castle of Windsor is 
seen standing on a detached mass of 
chalk, rising higher than the surface 
of much of the surrounding London- 
clay; in which last, on nearly all 
sides, 1 believe, deep modern wells 
have been sunk, without reaching the 
chalk, except, perhaps, by the noses 
of some of the augers, which have let 
up the springs into these wells. It 
appears to me probable, that this 
Windsor mass of chalk, is surrounded 
on all sides by those dislocating fis- 
sures, which the miners usually call 
faults, and has been lifted or thrust 
up 200 or 300 feet from its former po- 
sition; but, without these fissures 
around the Windsor chalk,” giving 
vent, as far as I know, to any remark- 
able or large springs of water, from 
the great water-charged mass of chalk 
which they intersect, and from which 
this mass seems to have been ele- 
vated. 
Another anomaly attending — this 
overflowing-well district around Lon- 
don, occurs in the vale of Ravens- 
borne, in the north-west corner of 
Kent, wherein the chalk strata lie 
hare, down as far as Deptford; and 
the edge of the London clay is in this 
valley, little, if at all, elevated above 
the level of the Thames ; and yet with- 
out this place producing any very 
great or notable springs of water, or 
without the district to the west of this 
Mr. Knowies on Improvements in Ship-building. 
37 
valley, being unfitted for producing 
overflowing wells, as I understand; 
which circumstances may, I think; 
have arisen, from a water-tight fault 
or fissure, filled with clay, crossing 
the vale of the Thames, near to the 
Ravensborne valley on the west, and 
elevating the strata on its eastern 
side. But having already somewhat 
extended this letter, and having a wish 
to mention several other matters, the 
results of my professional engagements 
and inquiries, relative to wells and 
borings, in the vale of the Thames, 
and many other places, I must reserve 
these for a future communication. 
Howland-street ; JOHN FAREY, 
July 8, 1822. Mineral Surveyor. 
—a— 
To the Editor of the Monthly Magazine. 
SIR, 
CORRESPONDENT, who signs 
“ Fact,” in your last month’s Ma- 
gazine, has taken the title of a work 
which I have lately published, on the 
present method of constructing ships, 
as practised by Sir Robert Seppings, 
as a text, for the purposes of abusing 
the inventor, and of conveying to your 
readers the notion, that all the im- 
provements which he has introduced 
are due to the ingenuity of others. 
It is pretty evident, that he has only 
read the title of the work in question ; 
for, if he had perused the book, he 
would most probably haye’saved him- 
self the trouble of writing, and me the 
pain of answering such incorrect and 
malicious observations;. and which 
are calculated only to make an im- 
pression on those who have not stu- 
died the subject. 
Ist. As to the mode suggested by 
Capt. Cowan, in the year 1808, “‘ of 
filling in the timbers, and making all 
solid.” Filling-in and caulking the 
frames of ships, as high as their floor- 
heads, has been practised in this coun- 
try as long as England has possessed 
a navy of any strength; and you will 
find, on reference to my work ‘ On 
Preserving the Navy,” (page 60,) that 
“Mr. Kirby, of Chatham-yard, pro- 
posed in the year 1763 to fill-in and 
then caulk the frames of ships, from 
their keels to the water’s edge.” This 
did not rest, prior to Capt. Cowan’s 
proposition, upon recommendation 
only; for Admiral Schank built in 
1800 a vessel, in Mr. Dudman’s yard 
at Deptford, with a solid frame. 
Qdly. The proposal of “ omitting the 
foot-waling, and substituting diagonal 
riders,” 
