The Sun.
London, England, 1835-10-02 00:00:00

D'ENTRECASTEAUX CHANNEL.

The following were yesterday posted at Lloyd's :-
4, Downing-street Sept. 30, 1835.

" Sir—l am desired by Lord alenelg to transmit to yoti,
for the information of the Committee at Lloyd's, the accom-
panying extract of a despatch which has been received from
the Lieutenant-Governor of Van Diemen's Land, from the
Captain of the Port at Hobart Town, containing various ob-
servations with regard to the navigation of that part of D'En-
trecasteaux's Channel, where the convict ship George 111.
was lately wrecked.
(Signed) "JAMES STEPHENS.
" To the Chairman of the Committee for
managing the Affairs of Lloyd's."

Extract of a despatch from the Lieutenant-Governor of
Van Diemen's Land, to the Secretary of State, dated
April 25, 1835
" I have the honour to enclose a very Important communi-
cation received from the Port Officer, and to submit that his
recommendation should be communicated to Lloyd's:—
" ' Sir—ln dwelling upon the circumstances of the disas-
trous wreck of the transport George 111., I bait been led
naturally to inquire how far the dangers actually known to
exist between the Actaeon Islands and the main have been laid
down: in doing so it appears to me that every danger at pre-
sent known is laid down with tolerable precision in the Aus-
tralian Directory, compiled from documents in the Hydrogra-
phical Office, and printed for the Hydrographical Office, Ad-
miralty, 1830, a work of the publication of which the Master
of that vessel was not aware. The rock on which this vessel
has been wrecked is described in a note quoted from the Syd-
ney Gazette, February 27, 1824, page 212 of that work. Un-
willing to make any observations that may seem to condemn a
passage which offers Bawl advantages, and which, I have no
hesitation in saying, I would, under all circumstances, gene-
rally select, I still consider it my duty to express the
opinion
that a communication be made to Lloyd's, recommending that
vessels avoid this passage until a proper sur.'nv be made of all
the dangers surrounding the Actaeon Islands, and between
them and the Western shore ; and advising in all b,:ses when
intending to run through D'Entrecasteaux Channel, I::'at a
vessel should stand to the Eastward from Whale Head,
E.N.E., with an offing of two miles. The Actaeon Island
should be well opened to the Eastward of Sterile Island be-
fore hauling up for the Channel.
(Signed) "' W. MORIARTY, Port Officer.
" To John Montague, Esq., Colonial Secretary:'

MANUFACTURE OF GUNPOWDER.

The following description of the nature and manufacture
of Gunpowder, by an able chemist, (Dr. Urc), will proVe
inter ing
:—:This explosive substance consists of an inti-
mate mixture, in determinate proportions, of saltpetre, char-
coal,,; and sulphur ; 2d is better in proportion, every thin..
else being equal, to the quitY of these ingredients. The
nitre, in particular, ought to hep,,fectly refined by succes-
sive crystallizations, and finally freed trim adhering water,
by proper drying, or by fusion in iron pots d: a regulated
beat. Nothing can surpass in these respects, the rui:e pre-
pared in the Government powder mills at Waltham Abhb;'•
It is tested by adding to its solution in distilled water, nitrate
of silver, with which it occasions no perceptible opalescence.
The sulphur ought also to be of the finest quality, and pu-
rified by skimming or even sublimation, if at all necessary.
The charcoal should be newly made ; it should burn without
having any sensible residium, be dry, sonorous, light, and
easily pulverized. The charcoal for gunpowder is made
either of alder, willow, or dog-wood, the latter being pre-
ferred—which are cut into lengths and ignited by iron
cylinders. It deserves notice that the proportion of
powder used for the several pieces of ordnance by the
Navy &c., has been reduited to one-third, in consequence of
1 the increased strength of the composition into which this
cylinder charcoal enters, compared with that manufactured
formerly from charcoal made in pits. The wood before
charring is carefully stripped of its bark. The three in-
gredients, being thus prepared, are ready for manufacturing
into gunpowder. They are first separately ground to a
fine powder, which is passed through paper scives, or bolt-
ing machines ; Qnd, secondly, they arc mixed together in
proper proportions. These do not seem to be definitely
determined, for they differ in different establishments of
great respectability, as is shewn by the following table :
Nitre. Charcoal. Sulphur.
Royal Mills at Waltham Abbey 75 15 10
French, for war
--, for Sportsmen
--, for mining ... . 65 15 20
Chaptal's proportions
Chinese ditto
Mr. Napier's ditto
Thirdly : the composition is then sent to the gunpowder
mill, which consists of two edgestones ofa calcareous nature,
turning by means of a shaft on a bedstone of the same nature
which give no sparks, as sandstone would be apt to do.
'`i this bedstone the composition is spread, and moistened
1 ‘.3, *mall a quantity of water as will, in conjunction with
the revniv*
init
1 wkth W.. :ones bring it into a proper body of cake,

but not of paste. The line of contact of the edgestoue is
constantly preceded by a scraper, which goes round with the
wheel, constantly scraping up the cake, and turning into the
track o`' the stone. From 50 to 60 pounds arc usually worked
alt once in each mill wheel. When the cake has been
thoroughly incorporated, it is sent to the corning-house,
where a separate mill is employed to form the cake into
grains or corns. Fourthly : here it is first pressed into a
hard firm mass, then broken into small lumps ; after which
the graining is executed by placing these lumps in sieves, on
each side of which is laid a disc of lignum v!tw. The sieves
are made of parchment skins, perforated with a multitude of
round boles. Several such sieves are fixed in a frame,
which, by proper machinery, has such a motion given to it,
as to make the lignum vitae runner in each sieve move round
with considerable velocity, so as to break the lumps of the
cake, an I force the substance through the sieves, forming
grains of several sizes. The granular particles are after-
wards separated from the finer dust, by proper sieves and
reel. Fifthly : the corned powder is next hardened, and
the rougher edges taken off, by being revolved in a close
reel or cask, turning rapidly on its axis. This vessel some-
,,,-,!tat resembles a barrel churn ;it should be only half full
at eat;2.l operation, and has frequently square bars inside,
parallel to .;.ts axis, to aid the polish by attrition. Sixthly ;
the gunpowder is now dried, which is done generally by a
steam heat, or by i:ansmitting a body of air, lightly heated
in another chamber, over canvas shelves covered with the
damp gunpowder.—Mining Journal.