The Sun.
London, England, 1859-01-12 00:00:00

PUBLIC GAS-LIGHTS.

Mr. BONE wished to know to whom the duty was
confided of inspecting the gas lamps throughout the
City during their burning at night?
Mr. DAw—The police.
Mr. BONE said that for a considerable time past
he had noticed that the amount of light in the
public lamps had been anything but what it ought
to be, and had not exceeded that of the old oil
lamp in many instances. Then the lanterns were
in such a filthy state that the little light they con-
tained was nearly obscured. This was a state of
things that ought not to exist, seeing that the last
year or two the commission had paid a much larger
amount than formerly for lighting the public
streets. (Hear hear.)
CHAIRMAN—It• is not my place to justify the
company in not fulfilling their contract, but for
some time past a combination amongst the men
has been going on which has threatened to deprive
London of 'gas-light. One company was obliged to
send the whole of their men away on one occasion
and to seek about the country for another class. It
is well they have been able to get over Christmas.
I know that the company that supplies us are
anxious to fulfil their contract.

Several members having stated that the gas sup-
plied to their private houses, as well as to the pub-
lic lamps, had lately been deficient in quantity and
inferior in quality, the clerk was ordered to call the
attention of the company to the matter by letter.

DIABOLICAL ATTEMPT TO BLOW UP
• A SHOP IN SHEFFIELD.

Yesterday, another of those diabolical and un-
manly attempts to destroy life and property for
which the lower orders of the working cutlers of
Sheffield have unfortunately become somewhat
notorious of late years, was made at the shop of
Mr. Samuel Poole, butcher, in the Wicker, Shef-
field. Mr. Poole's brother-in-law, James Linley, a
saw grinder, and his wife and family, live with
him, and have done so for some months past. Up
to yesterday nothing extraordinary occurred,
though it was well known that Linley had aroused
the bitter hatred of a few men in consequence of his
determination to carry on his trade without becom-
ing a member of, or having any connection with,
the saw grinders' trades union. It may be well
here to state, in order that the proceedings which
we are about to describe may be the more readily
understood, that about 12 months ago, at an early
hour in the evening, when the fog was so thick as
to render objects at a' short distance invisible, Lin-
ley was sitting on a bench near the window in the
house of a friend in Nursery-street, when he was
fired at from the street, and knocked off his seat.
The bullet penetrated two or three thick coats, but
before it reached his body its force was spent, and
no personal injury resulted. On Monday night
last Mr. Poole, Mr. Linley, and their families re-
tired to rest at the usual time, and about seven
o'clock yesterday morning Mr. Poole got out of
bed, and just as he was about to dress himself he,
and the remainder of the inmates of that house and

the other houses in the neighbourhood, were greatly
alarmed by hearing a very loud report, as of an
explosion of gas or gunpowder. The explosion was
so violent as to shake the premises from top to
bottom, and immediately after the report the noise
of falling glass and other things was heard, both
on the roof of the house and on the flags in
front of the shop, and the p' ace was completely
filled with soot and dust. When Mr. Poole
and Mr. Linley had somewhat recovered - from
the fright, they went down stairs in , order
to ascertain the cause of the explosion. Believ-
ing that the report might have been caused by an
escape of gas in the cellar, and that if so the cellar
might still be full of gas, they were afraid to ven-
ture there, and at once sent to the gas office and to
the Town-hall for assistance. A gas man and In-
spector' Linley went to the place, and on examin-
ing the cellar, found that an explosion of gun-
powder had taken place. In the cellar was found
the shattered remains of two tin cans ; one appa-
rently a sauce-pan, and the other a smaller can of
the same shape as those with which machinery is
oiled. A sort of fuze, which had been on fire, was
also found, and there was every appearance of a
violent explosion having taken place. The smaller
can appeared to be placed inside the other, but
whether both cans had been filled with combus-
tibles or not is known. The cellar grate in front
of the shop was unfortunately left unfastened on.
Monday night, and the fellows who perpetrated the
cowardly offence, after taking the grate up, lowered
the explosives into the cellar by a tarred rope, and
it is presumed that the object of using a tarred rope
was to fire the premises. In this, however, they
were not successful. The force of the explosion
was so great that it burst off the iron bar which

secured the shutters, tindfoicedtheshutte; on the
footpath. A window looking into the shop, and
near the top of the cellar steps, was forced forward,
about two inches, and a 'window on the top of the
house was forced-completely out, and a part of it
was afterwards found in a dyke ,behind the pre-
mises. It is supposed that the force of the explo-
sion has been greatly lessened by the cellar and
shop dciors being open, and thus leaving the cur-
rent caused by the explosion an unobstructed pas-
sage to the attic window at the top of the house.

hydraulic rams, which are probably the longest
apparatus' of the kind in the world, being nearly
30 feet long, and having a stroke of 25 feet. These
are of course properly set and secured in solid
masses of masonry to resist the tremendous pres-
sure which is brought to bear on their foundations,
when the apparatus is in action. To the head of
each of the pistons of these rams -is attached a strong
wrought-iron cross-head. Fastened to each pair of
hydraulic rams, and extending across the docks,
are massive trussed iron girders, weighing upwards
of 60 tons each, and capable of sustaining a weight
of nearly 300 tons. There are thus 16 of these
iron girders, traversing the dock from side to side,
at distances of 20ft. apart, forming a gigantic frame-
work, capable of sustaining a weight of nearly
4,000 tons, or far greater than that of the ordinary
run of large first-class ships, To avoid the risk of
the rams breaking -(which would be a very consi-
derable one, owing'to their unusual length, and the
great weight they have, to support when in, use)
the cross heads to which the iron girders are at-,
tached run in massive 'cast iron guides, which rise
some 28 feet above the water, • The iron pontoons
which are used for floating the ships after they are
lifted, and during' their .repair are. to be eight in
number, all 60 feet broad, and 'varying in length
from 240 to over $OO feet. At ,present, however,
there is only °nein use and •another approaching
completion, both- of • which are of the minimum
length of 240 feet.. They are constructed of boiler
plate iron, strengthened, of course, with stout
wrought iron girders, secured transversely across
the pontoon, at intervals of three or four feet. 'They
are extremely light, weighing altogether little more
than 300 tons, though the great surface which they
present to the water (14,400 superficial feet) enables
them to support a weight ,of 2,000 tons, with an
immersion of little over 4 feet. At one end of each
of these pontoons is placed
.a large valve which,
opening and shutting with a kind of screw break,
can be sunk or rendered water tight in a very few
minutes. The modus operandi of lifting a vessel is
as follows :—The iron pontoon is first moored over
the lifting dock, the valves are opened, and it is
allowed to sink until it rests upon the irpn girders
attached to the ram. The ship to be docked is then
moored immediately over the pontoon, and the force
pumps worked until the keel rests upon the pontoon..
The wooden dogs which are fixed so as to slide back-
wards and, forwards on the floor of the float are
then, by means of ropes, drawn under the sides of
the vessel so as to support her in an upright posi-
tion, and prevent her from •" canting over" when
she is raised out of the water. When all these pre-
liminaries (which in their performance do not
occupy much more time than that taken to describe
them) have been properly adjusted, the hydraulic
pumps are again set to work, and the whole appa-
ratus, pontoon, ship, and all, is fairly raised out of
the water. When all the water has discharged itself
through the valves in the bottom of the pontoon,
they are firmly closed water-tight by means of the
vulcanised, India rubber seams, and the water being
allowed to escape from the hydraulic cylinders, the
rams, with their attached girders, sink down, leaving
the pontoon floating with the vessel in it high and
dry. The whole operation, from the very commence-
ment, does not occupy more than one hour or so. If
the object of docking the ship be merely to examine
the bottom or to execute some slight repair, which
will occupy but a- few hours, the pontoon is not
moved from the lifting dock ; but should the neces-
sary repairs be of such a nature as to occupy any
length of time, it is towed away into one of the eight
shallow docks built for the purpose, the depth of
water in which varies, according to the tide, from
six to eight feet. -When the scheme is fully carried
out, it is intended to have regularly fitted work-
shops placed on the banks of each of these pontoon
basins for the repair of both steam and sailing ships
constructed of either iron or timber. When it is
wished to float a ship again, the pontoon is moored
in the lifting dock, and the girders are raised up
sufficiently high just to take the weight of the ship
off the pontoon. The valves of the latter are then
opened, and at the same time water is allowed to
escape from the hydraulic cylinders, so that the
whole apparatus' quickly, sinks, effectually launch-
ing the ship again in about ten minutes. The great
advantages attendant upon having 'a simple and
efficadious apparatus of this kind in connexion with
a large dock company, are too manifest to require
comment. By it the expense of docking a ship is
much reduced, and at the same time infinitely
greater facilities are afforded for the
.performance
of the operation, and the time occupied by it re-
duced in a mostimportant degree. Should it become
necessary to dock a ship just as she is preparing to
sail (as is very frequently the case), the operation
can now be immediately performed in less than two
hours, in any state of the tide, and without there
being any necessity to discharge the cargo. If the
necessary repairs were of a trifling nature, the ship
might aonin be launched and pursuing her course
down the Thames within four or five hours. The

hydraulic pumps and rams connected with the
"lift" are of course the most important and inte-
resting parts of this gigantic apparatus. They are
worked by a 50-horse power, combined high and
low-pressure, engine. The water is pumped from
the engine-house through the commoit pipe to a
reservoir in . the valve-room (where .all.the tubes
through which the hydraulic cylinders are supplied
concentrate) at a pressure of about a ton to the cir-
cular metre. The valves in this room are so arranged
that the rams may be Made to act together in sets
of six, or each may be put into action :p3rfectly
independent of the other. These complicated series
of valves are of course, during the operation of.lift-
ing, under the charge of a competent engineer,
who, by increasing or diminishing the action of
each pair or series of rams, can cause the ship to be
raised,either perpendicular or in any other desired
position. It has been said that the water is pumped
into the hydraulic cylinder at a pressure of one ton
to the circular inch, which gives a lifting force
with the whole 32 10-inch rams of 3,200 tons.
This is the ordinary working pressUre when ordinary
ships of less than 2,800 tons weight have to be
raised. But with heavy laden vessels a much
greater force would :be required. The moveable
portions or the pistons of the rams, together with
the cross heads, iron girders, &c., weigh about
1,100 tons, and the iron portion about 300 tons
more ; but as about 1,000 tons of this iron work is
never raised above the water, 100 tons must be de-
ducted from this for displacement. Thus about
1,300 tons of the ordinary working force of 3,200
tons is consumed
.in raising the apparatus itself,
leaving only 2,900 ton's for the weight of the ship.
As none of the pontoons yet constructed will carry
more than about 2,000 tons, the ordinary force is
sufficient.' But should it at any future time be
deemed necessary to raise a ship and cargo of
greater weight, the rams would easily bear a pres-
sure of two tons to the Circular inch, which (sup-
posing the .rest of the apparatus would resist such a
strain) would give an available lifting power of
about 5,000 tons. This invention is doubtless only
the precursor of great and sweeping changes in the
method of both launching and 'docking ships to be
effected'through the agency of the hydraulic ram,
which supplies us with such a ready and efficacious
means of concentrating mechanical power.