The Sun.
London, England, 1851-05-16 00:00:00

upon the peculiar claims which the society had upon
the sympathies of the public. The object of the so-
ciety was, in the first place, to afford temporary as-
sistance to female teachers. No less than 879 ladies,
in the most varied positions of distress, almost always
originating from sickness brought on by the self-imposed
labour of the daughter for the parent's support, had
received such assistance as amounted altogether to
4,9811. 9s. His Lordship then stated the other object
of the society, and said that he had visited that branch
of it called " The Home," and he expressed the great
satisfaction he derived from the manner in which that
department was conducted. The Noble Marquis then
made a very powerful appeal to the company on be-
half of vsonsen, who, as he observed, having been
educated in circumstances of comparative affluence, had
been obliged, in af%er life, to devote their talents to
the training and rearing up of the children of our no-
bil!!y ; and he pointedly alluded to the very cqeivecal
position in which those ladies were placed, depend-
ing as they did upon the generous and forbearing treat-
ment they experienced from those to the advantages of
whose offspring they were devoting the best energies
of their lives. The secretary stated that the dona-
tions were very liberal :-250/. from her Majesty, 201.
from the Duke of Cambridge, 501. from the Noble Chair-
man (the Marquis of Westminster), 101. from Earl
Fitzwilliam, 101. from Lord Feversham, and various other
similar contributions, amounting altogether to 1,4801.
There was a large assemblage of ladies at the dinner,
the greater part of whom were patronesses of the institu-
tion; the rest were the amiable and interesting recipients
of its benefits, to whom the Marquis of Westminster took
every appropriate occasion to evince the most gentle-
manly and cordial recognition.

INSTITUTION OF CIVIL ENGINEERS.
(William Cubitt, Esq., President, in the chair.)
The paper read on Tuesday was " On the Pneumatic
Method adopted in constructing the Foundations of the
new Bridge, across the Medway, at Rochester," by Mr.
John Hughes, Assoc. Inst. C.E.
This bridge was described as being designed to con-
sist of three large openings, a central one of 170 feet in
width, and two others, each of 140 feet in width,
spanned by cast-iron segmental girders, and of a passage
to admit masted vessels to the upper parts of the river,
across which a moveable bridge would be placed. Each
of the river piers occupied au area of 1,118 square feet,
and rested upon a series of cast-iron cylinder piles, 7
feet in diameter, placed 9 feet apart longitudinally, and
10 feet transversely, so that there were fourteen under
each pier. The cylinder piles in the abutments were 6
feet in diameter, of which the " Strood" abutment re-
quired thirty, and the " Rochester" abutment twelve.
Each pile was composed of two, three, or more cylinders,
9 feet in length, bolted together through stout flanges;
the bottom length had its lower edge bevelled, so as to
facilitate the cutting through the ground. The bed of
the river was orignally presumed to consist of soft clay,
sand, and gravel, overlying the chalk, and accordingly
the application of Dr. Potts' pneumatic method for
forcing the cylinder piles into the ground, which had
been successfully carried out in similar positions, was
contemplated; but after a few trials, the ground was
found to consist of a compact mass of Kentish rag stone,
so that the mere atmospheric action upon the piles,
induced by a partial vacuum, would be ineffective in such
a situation. It was therefore decided that the pneumatic
process should be reversed, so as to give each pile the
character of a diving-bell; for which purpose one of the
cylinders, 7 feet in diameter, and 9 feet in length, had a
wrought iron cover securely bolted to it, through which
two cast iron chambers, D shaped in plan, with a sec-
tional area of about 6 square feet, appropriately called
" air locks," projected 2 feet 6 inches above the top of
the cylinder, and 3 feet 9 inches below the cover. The
top of each "air lock" was provided with a circular open-
ing, 2 feet in diameter, with a flap working on a horizantal
hinge, and an iron door, 2 feet by 3 feet 4 inches, with
vertical hinges below the cover; each " air lock" was
also furnished with two sets of cocks, the one for
forming a communication between the cylinders and the
chamber, the other between the chamber and the atmos-
phere. Compressed air was supplied to the cylinder
pile by a doable-barrelled pump, 12 inches in diameter,
and 18 inches stroke, driven by a 6 H. P. non-condensing
steam engine. At first the expelled water was made to
pass into the river, from beneath the lower edge of the
pile, but when the stratum became so compact as to op-
pose a high degree of resistance to the passage of the
air, an outlet was formed through the side of the upper-
most cylinder, by the introduction of a pipe, having the
form of a syphon, the long leg of which reached to the
bottom of the ,pile, and was subject to the pressure
of the condensed air on the surface of the water within,
whilst the short leg, leading into the river, had the effect
of relieving the amount of compression, provided a va-
cuum was once obtained in in the body of the syphon.
Such an effect was readily produced by connecting the
summit with the exhaust side of the air pumps, by a
pipe which could be opened or closed at pleasure.
'Co insure the downward motion of the pile, and to give
it a weight which should be at all times superior to the
upward pressure, two stout trussed timber beams were
laid on the top of the cylinder, in a direction suitable for
bringing the adjacent piles into action as counter-
balance weights, by four chains passing over cast iron
sheaves.

Two light wrought iron cranes were fixed inside the
cylinder, the jibs of which swept over the space between
the air locks and windlasses, inside and outside, for the
purpose of hoisting the loaded buckets and lowering the
empty ones.
The method followed in working the apparatus was
found to be so simple in detail, as to be perfectly
intelligible to all the workmen employed. The
pumps being set in motion, the flap of one of the
air locks, and the door of the other, were
closed; a few strokes compressed the air within the pile
sufficiently to seal the joints, and whilst the pumping was
in progress, the men passed through tho air locks to j
their respective stations. When the water was shallow,
the pile descended by scarcely sensible degrees, as fast as
the excavation by hand permitted; but when the water
was deep, the excavation was carried down full 14 inches
below the edge of the pile, which then descended, at
once, through the whole space, as soon as the pressure
was eased off.
The most perfect certainty and success had attended
the employment of this simple system, and as it pro-
mised to afford considerable assistance to engineers in
the prosecution of similar works, the author laid the ac-
count before the Institution with the sanction of Mr.
Cubit, President Inst. C.E., the Engineer-in-Chief, and
:11esara. Fox, Henderscn, and Co., the contractors for
the works.
Mr. Eaton Hodgkinson, who had been recently elected
an
mem-
ber, were presented
member, and the Chevalier Conrad,
letrt, presented to the meetin, on attendin
sident for
the Brat time since their election. g g
t w
as again announced from the chair, that the Pre-
the nr-anbers'
s Annual
Pre-
day evenin Co:versus/one would be held on Tues-
aMay 27th,which the co-operation of
collection Of models of engineering con-
structions,inseeptcieimens of works of art, might be
made ; ad the
May 20, when the following paper
adjourned until Tuesday,
the Isthmus of su,
z,
and the
paper would be read:—" On
Joseph Glynn, M. Inst. C.Ee. Canals of Egypt," by Mr.

it
ONERyanitaFwOoußld
'ICE
mmoDF oLEdsE
,z.
A report has just been made I; .5, a special commit-
ttee of the Middlesex magistrates, appointed
onviihthaet
17th of October last, "to consider whether
eer
be for the benefit of the county that an
different arrangements should be made for the
per-
formance of the duties now devolving upon ti
coroners, or respecting the remuneration annexed
thereto ; also, whether it is desirable that a medical
stating officer should be appointed to the coroner's court."
,e,nrdar. 3
The report, which is of some length, enters into the
subject of the inquiry with considerable minuteness,
but the report of it may be shortly given. After
that the committee wore favoured with the at-
of Mr. Wakley Mr. Baker, Mr. Bedford, and
al iiggs, the c-r : Vr. Jardine, Mr. Arnold,
and_mr. ‘. one,s ; A.i. .
Broughton, the police magistrates ; and wi'ch
coulartmicat.,
1 oas from Mr. Paynter and i‘lr. Yardley,

THE

northern part of the mine, where the bunches of lead are,
and with the exception of dressing the ore for market,
in consEquence of the men not having sufficient air to
work in.

At the Wheal Lovell meeting held on the 9th instant,
a dividend of 21. per share (8601.) was declared.
At the South Wheal Frunces meeting, held on the sth
inst., a dividend of 81. per share (1,9841.) was declared,
leaving a balance in favour of the adventurers of 1811.
12s. 4cl.

At the Carwinnen meeting, on the sth inst., a call of
lOs. per share was made.
At the Crane and Bejawsa meeting, held on the 6th
inst., the accounts for January and February were audited
and passed, and a call of 21. per share was made.
At the East Tywarnhayle meeting, ,on the 6th inst.,
the accounts showed a balance in favour of the adventu-
rers of 353/. 16s. Bd. A call of 31. per share was made.
At the Wheal Mary Emma meeting, held on the 9th
inst., the accounts showed a balance in hand of 3111.

18s. 3d.
Copper ores far sale on Thursday, May 22, at the
Royal Hotel, Truro:—Devon Great Consols, Wheal
Josiah, Wheal Maria, Wheal Fanny, and Wheal Anna
Maria, 1,575; West Caradon, 329; Fowey Consols, 261;
Wheal Friendship, 203; Bedford United Mines, 144;
Poldice, 133; Wheal Maidsn, 36; Wheal Crebor, 33;
Wheal Jewel, 25; Peopol Regulus, 25; Copper Bottom,
24; Point Regulus, 18. Total, 2,806 tons.
Exports of metals from London for the week ending
Thursday last :—lron, 534 cwt. to Malta and Alex-
updris; iron nails, 22 cwt. to Caps of Good Hope; tin,
12 cwt. to Gothenburg, and 199 cwt. to New York;
blacklead 67 cwt. to Dunkirk, and 20 cwt. to Rotterdam;
spelter, 100 cwt. to Rio Janeiro; quicksilver, 168 lbs.
to Stockholm, 737 Ib3. to Lisbon, 15,1201 b. to Dunkirk,
and 2131 b. to Gottemburg.

GOVERNESSES' BENEVOLENT
INSTITUTION.
This institution held its eighth anniversary at the Lon-
don Tavern on Wednesday, when the Marquis of West-
minster presided, in the absence of the Duke of Cam-
bridge, who wrote a letter of apology, saying that he
was obliged to attend a dinner given by her Majesty at
Buckingham Palace. We regret to say the meeting was
not very numerously attended, but the Noble Chairman
was nevertheless most respectably supported by
Lord Feversham, the Hon. G. Rice Trevor, M.P.,
Mr. E. King Tenison, M.P., Mr. E. Baker, jun., Mr.
G. F. Carden, Mr. W. Ewart, M P., Mr. B. Edgington,
Mr. F. W. Fairholt, Mr. W. Gilpin, Mr. J. W. Hale,
Mr. G. Henderson, Mr. H. N. Nissen, Mr. F. T. Pratt,
and several other gentlemen with whose names w
eare
not acquainted. After the usual loyal toasts, the Noble
Chairma-a proposed " Success to the Governesses'
Berevolent Institution," and, in doing so,
.he dwelt