The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1839-07-19 00:00:00

SELECT EXTRACTS.

THE DAGUERREOTYPE.—A few days since M. Daguerre
exhibited in one of the rooms attached to the Chamber of
Deputies, several specimens of the products of the Daguerreo-
type. Among them were views of three streets of the capital,
the interior of M. Daguerre's atelier, and a group of busts in
the collection of the Louvre. The deputies who examined
them, and who.continued to crowd the room throughout the
day, were particularly struck with the marvellous minuteness
of detail which these views, and especially those of the streets,
exhibited. In one, representing the Pont Marie, all the
minutest indentations and divisions of the ground of the
buildings, the goods lying on the wharf, even the small stones
under the water at the edge of the stream, and the different
degrees of transparency given to the water, were all shown
with the most incredible accuracy. The use of a magnifying
glass revealed an infinity of other details quite undistinguish-
able by the naked eye, and more particularly in the foliage of
trees. The antique busts are said to have been rendered by
this method with very great beauty of effect. The chemical
substance upon which the light acts, according to M. Da-
guerre's method, is laid upon the sheets of copper, which for
the drawing, exhibited on Saturday, were about nine or ten
inches by six or seven inches. The expense of such plates
M. Daguerre estimates at about 3fr 50c each, but he expects
that considerable reductions may be ultimately made in their
cost, and that the improvement of his method will render it
applicable to other substances not metallic. —G alignani.
COST OF DIFFERENT LIGHTS.—At a late meeting of the
institution of civil engineers, a paper was read, entitled "Ex-
perimental Researches upon the Cost of Light afforded by
different Lamps and Candles," by Andrew Ure, M.D. F.R.S.
&c. The author, having instituted a series of experiments
to determine the advantages of Mr. Parker's new hot oil
lamp, adopts as the standard of comparison the French me-
chanical lamp, in which the oil is raised by machinery, so as
continually to overflow at the bottom of the burning wick.
The relative illumination was determined by the well-known
method of the equal intensity of shadows, and verified by that
adopted by Professor Wheatstone, namely, by the relative
brightness of the opposite sides of a revolving ball. The
chimney of the new lamp differs from the chimnies of other
lamps in having a bell-mouthed glass chimney, and above it
a chimney of iron, with a parted diaphragm for the purpose
of causing a certain portion of the heat of the flame to rever-
berate against the interior cylindric cavity of the oil cistern.
The bell mouth is formed in a mould, and is far better suited
for producing a steady flame than the rectangularly contracted
chimney of the mechanical lamp. The intensity of the sha-
dows from the mechanical lamp and hot oil lamp of a wire a
few inches long, and of the thickness of a crow quill, was
equal, at a distance of 10 and 11 feet respectively; their re-
lative illuminations being as the squares of these are, 100 and
121 respectively, and the consumption of the best sperm oil
was 15.2 and 11.6 grains per minute ; the relative cost of il-
lumination for this oil would then appear to be 50 per cent
in favour of the new lamp. On trying southern whale oil.
the cost of illumination appeared to be about one-third that
of the mechanical, and one-half that of the hot oil lamp, with
sperm oil. The author tried many other substances, and,
comparing the various illuminations, concludes that the hot
oil lamp with soutthern whale oil aro, ds on economy of light
nearly 12 times greater than sterine or German wax =die!,
71 tunes greater' than tallow mould, 11 times greater tlan
cocoa nut, 81 times greater than Palmer's, 171 times greater
than spermaceti, and 18 times greater than wax candles.—
The author had also compared the illumination produced by
one of the Fresnel's lamps deposited at the Trinity House.
The lamp consists of four concentric circular wicks, placed
in a horizontal plane, the innermost being 7-Bths of an inch,
and the outermost 31 inches in diameter. The intensity of
the shadows from this and from the mechanical lamp were
equal at a distance of 13 feet 3 inches, and 4 feet 3 inches
respectively; taking the squares of these, the Fresnel lamp
gives about nine times the light of the mechanical, which
latter may be assumed are equal to that of eleven average wax
candles.. On comparing one of the best argand lamps with
the mechanical, the former was to the latter as 10 to 11 ; so
that the illumination of the Fresnel lamp, instead of being,
as has been asserted, equal to 40 argand lamps, is not equal
to more than 9.6 of those lamps. In the Bude light a small
stream of oxygen is sent up through a small tube within a
burning wick, which is 5-Sths of an inch in diameter, and
the flame of about 3-Bths of an inch. The i luminating power
is equal to to about 30 wax candles. Dr. Ure also examined
the illuminating power of different kinds of wax candles, and
found that the light from a long-three and a short-three was
the same, or 1-11th of the mechanical lamp ; also the light
emitted from one of the six to the pound was very little less,
being 1-12th of that of the mechanical lamp. The consump-
tion of wax in a long or short-three may be taken at 126 grains
per hour, and in a short six at 125 grains per hour. Wax
contains 81.75 parts of carbon in every 100 parts, and the
combustion of these 100 parts produces 36 parts of cai bonic
acid ; consequently a wax candle will generate per hour about
375 grains of carbonic acid, or 800 cubic inches of gas. Now
an average-sized man developes and exhales from his lungs
1,632 cubic inches of gas per hour ; thus the combustion-of
two ordinary wax lights injures the air to about the same (Ix-
tent as the breathing of one man.—Athen mum
PROPULSION OF A STEAMER BE THE ARCHIMEDZAN
SCREW.—At a late meeting of the Institution of Civil En-
gineers, a paper was read "on the dimensions and perfortn-
ances of the Archimedean steamer," by George Rennie,
F.R.S., &c. The method of propulsion, by means of a hori-
zontal spiral screw, applied by Mr. Smith, in the Archimedean,
has frequently been attempted, and many authors have ex-
pressed opinions upon its applicability. The dimension% of
the Archimedes are :
Length of vessel
Breadth
Depth of hold
Burthen, in tons
Length of engine-room
The vessel draws 10 feet water, carries three masts, and
sails schooner fashion.
Power of engines collectively, 90 horses.
The crank shaft is driven from the connecting rods at-
tached to the piston rods of each cylinder.
Length of stroke, 3 feet; 30 strokes per minute.
The speed of the propeller is gained by wheel-work, and
communicated by a shaft passing beneath the cabin floor, and.
traversing the stern-post of the vessel. The diameter of the
screw is six feet, the length eight feet, and consists of spiral
oblique wrought-iron plates, attached by arms to the shaft.
The weight of engine, boiler, and machinery, is about 64
tons. Upon the first trial of the Archimedes, the log indi-
cated 8.5 miles per hour, the vessel readily answered to the
helm, and performed the several movements required. Upon
the second trial, the vessel left the Brunswick Dock at flood-
tide, and reached Gravesend (21 miles) in 1 hour 45 minutes.
Upon the following day, she arrived at the Nore (22 miles,)
with the tide, in 1 hour 40 minutes ; and subsequently towed
a yacht of 50 tons up the Medway with scarcely diminished
speed. From Sheerness, the Archimedes reached Ramsgate
(45 miles,) in 4 hours 30 minutes, The screw was here re-
duced in diameter; and, on leaving the harbour against a
heavy tide and N.E. wind, she made five knots, and gave
great satisfaction. The sails were set upon rounding the
Foreland, and the speed was increased to 9, 91, and 40 miles
per hour, or 14 miles with the tide. Upon her second voy-
age to Portsmouth, the measured mile was performed with
the tide in four minutes. The weather was unfavourable,
and wind high : the distance, 194 miles to Portsmouth, occu-
pied 21 hours : her average speed upon the return to London
was nine miles per hour. —At henaum.
PORTRAIT OF AN AFRICAN MONARCH.—We very soon
became acquainted with the sable potentates who reign over
the neighbouring swamps, and who all assume the title of
kings. There was old King Fourday with his three sons,
King Jacket, King Gun, and King Boy. The latter has
already required some renown by having ransomed the bro-
thers Lander, who, it will be remembered, were captured by
the Ibu people in their voyage down the river. We found
him on our arrival bargaining with the master of a palm oil
ship, for the sale of a promissory note which had been given
him in payment of the ransom ' • and in the course of the ne-
gotiation he received a hearty slap on his royal jaws for having
given the lie direct. I mention this little incident in order
to put my readers at once in possession of the kind of diplo-
macy which is practised by white traders at these courts.
Notwithstanding their high-sounding titles, these pseudo-
kings are but petty traders, who have a few canoes and
slaves, and, in consequence, possess a certain influence with
their countrymen. Fourday is a benevolent-looking old
man : he was quite delighted with a present of a scarlet
uniform coat, and sat in it the whole day, drinking raw rum,
and saying, " Very well." to everything; which, I believe, is
the amount of his knowledge of English, though he seemed
to think it expressed volumes, if we might judge from the
variety of tones in which he uttered it. His people did not
appear to pay him much respect, for when he could contain
no more rum they allowed him to stagger to his canoe, none
of his slaves or attendants putting themselves in the slightest
degree out of the way to assist him. Indeed he would have
vacated the throne for a watery grave, but for the assistance
of our sailors, who remarked, as they hoisted him over the
side, that he "had very nearly lost the number of his mess."
It is quite astonishing to witness the quantities of raw spirits
which these people swallow. Boy had always a full decanter
before him, which, with a very little assistance from his mate,
or prime minister, be never failed to empty. Indeed, he
sometimes called to have it replenished : when he used very
little ceremony, merely saying " Bring rum." He is' too !t
good a judge of the cratur to allow it to be watered. The :,,
natives danced and sang halt the night on the shore abreast 4*
of us, and shouted with a speaking trumpet, of whielr instru- .td
anent they are very fond, the chief frequently using it to hail
the man next to him in the canoe ; but its principal app;ica-
lion is in the invocations to the Deity or Djusebu the4rrate
quite delighted.Witix the supernatural tones of the echo, and •
deem these answers to be favourable, being neither dixo/410
nor dissentient.--United s6o3.vitv

105 feet.
20 2-10ths.
12 5-10ths.
230
38 feet. •