The Sun.
London, England, 1842-12-30 00:00:00

ADELAIDE GALLERY.

COMBUSTION. BY REFRACTED ARTIFICIAL
LIGHT.

Last evening .Dr. Atkins delivered • a lecture upon
the Boccius Light, • which he illustrated by experi-
ments of great novelty and interest, with the Colos-
sal Burning Lens, lately brought into use in this In-
stitution. The Learned Gentleman commenced by
stating that all bodies are divided into combustible
and incombustible, oxygen being the only supporter
of combustion, and the atmospheric air 'itself sup-
porting combustion only by means of the oxygen
which it contains. A change takes place in the
oxygen by its combination with the burning bodies,
so , that it becomes incapable of supporting respira-
tion or combustion, and affects vegetable colours,
which were before unaffected by it. All combustible
matters commonly burnt are composed of carbon and
hydrogen.- The Lecturer separated the oxygen and
hydrogen composing water, and burnt the latter ;
after which he produced water by the deflagration
of, the two gases. In producing artificial light, un-
less solid matter is introduced into the flame, the
latter is but slightly luminous. He showed that the
flame of Oxygen and hydrogen burnt together gives
little light, although possessing great heating power,
but when that flame is applied to a piece of lime, the
light produced is very great. The object, therefore,
sought in the improved method of procuring arti-
'ficial light, has been to bring the flame to act upon
-solid 'matter, so that it becomes incandescent, in the
most convenient way to produce the greatest amount
Of light,-with the least consumption of materials. The
,irOde of illumination, now most familiarly known as
-the Bude light, was first 'exhibited by the late Sir
-Humphrey Davy, at the IWO Institution, and the.
fifilure of its first application-to/the lighting of the
House of Commons by Mr: Gurney, was occasioned
`by the:difficulty of regulating the amount of light
and procuring the necessary supply Of oxygen. Gurney
and Boccius at the same time devised new kinds of
burners, to remove that defect. By the contrivance
of the latter inventor, of which the lecturer gave a de-
tailed description, the supply of oxygen is rendered
unnecessary, and there is no s.noke ; the light being
obtained at due-fourth of the expense required for the
same amount of light as was produced on Mr. Gurney's.
plan. For the better understanding of the 'experi-
ments which he was about to make with the Colossal
Burning Lens, it was necessary to explain that each
of the seven rays into which a pencil of solar light
may be divided by the prism, consists of three distinct
portions—an illuminating, a calorific, and a chemical
ray. External to the red ray is the greatest amount
of heating, or calorific rays ; and external to the violet,
the greatest amount of chemical rays. It had long
been doubted, and even denied, that artificial
light could transmit heat through glass and
other transparent bodies—in other words, it was
held that bodies diapbthermous to the rays of the
sun were not diaphthernious to those of artificial light.
It was shown,:however, by Meloni, that glass allowed
a small quantity of heat to accompany those rays,
but not so much in proportion as accompanied the
solar in their passage through the same material.
Now, the important point in the discovery which Dr.
Atkins had made by means of the Colossal Lens, was
that the heat of artificial light is refracted, reflected,
and transmitted by glass. It is reflected from a para-
bolic reflector to the lens, in paningthrough which it
is refracted, and then transmitted to, and concentrated
in, the focus on the other side: In this, the resem-
blance of the Drummond Light to that of the sun was
greater than was found in any other mode of artificial
illumination. His success in making the discovery
was to be attributed to the great powers of this une-
qualled lens. The history ofthe instrument was curious,
and not without interest. It is believed to be the same
that was originally constructed for the destruction of the
Emperor Maximilian, by concentrating the rays of the
sun upon his head as he passed in procession through
a city of the Netherlands, the thirteen provinces of
which became . subject to the- oppressive yoke
of Austria by 111aximilian's marriage with
the heiress of Charles of Burgundy. The
design was discovered, and the constructor of the in-
strument was put to death. This occurred shortly
before the' end of the fifteenth century, so that the
-lens is about 350 years old. It was some time in the
possession of the illustrious Lavoisier ; from whom
.itqassed.into the hands of a Frenchman, who sold it
for a small sum to the founders of this institution.

here some experiments were made with it by Mr.
Maugham, who succeeded in melting three ounces
of copper in its focus by the sun's rays. It was after-
wards laid aside as useless, or employed only to re-
present a revolving signal on the top of Mr. J. L.
Stephens' signal telegraph for railways. The pre-
sent talented proprietor of the Adelaide Gallery found
it amongst the lumber, and in testing its great powers
succeeded, on Monday last, for the first time, in
burning,phosphorus in its focus by refracted artificial
light, thus determining an important and long dis-
puted question in natural philosophy. The Lec-
turer repeated the experiment last evening with
and to the great satisfaction
opferfe success,
act
crowded
dss
audience. The Colossal Lens is
three feet in diameter, and weighs three cwt.
Such another could not now be made in this country,
as the regulations of the Government would not allow
the necessary proportion of lead to be used in the
manufacture of the glass.

--
A letter fram Rome says :—" It is well known
that Lord Shrewsbury is having a church built at
Ascott, near
Birmingham, dedicated to St. Gillers.
His Lordship,
a generous and liberal protector of the
fine arts, and particularly those referring to religion,
has entrusted to the clever painter, Edward Hauser,
of Basle, the execution of a magnificent painting,
which is to be the principal ornament of that church,
the building of which has been entrusted to Mr.
Puggein."
LETHENDY CAsE.—The action of damages, at Mr.
against the majority of the Presby-
teryfbr refusing to take him on trials,
e of
&c. which
hiciDnahsutwl'iankeed' scsieidown for trial by a jury in the.first
division of the Court of Session to-day, has been dis-
charged. The Lord President, after communicating
for a few minutes with the Dean of Faculipand Mr.
Rutherford, stated yesterday publicly from the bench,
that the Court, with consent of the counsel for the
parties, deemed it proper to postpone this trial. The
reason for this we understand is, that three other
important causes, involving much 9f the law which is
applicable to this case, are expected
.to be heard and
decided immediately after the Court meets ; and
hence the Lethendy case will not be tried till the
Spring sittings.—Scotsman,
raThe General Steam Navigation Company's vessel
the Giraffe, from Rotterdam, arrived off the Custom
House yesterday at twelve o'clock at noon, with the
Dutch 132111

TO CORRESPONDENTS
An " Old Subscriber" is informed, that we never in-
sert marriages Or deaths on anonymous authority.

THE WEATHER.—SUN OFFICE, DEC. 30.
THERMOMETER, Lowest, 50 ; Highest, 56 : Noon, 55

BAROMETER, 30.25.—W1ND, W.
NOTE.—The number 32 on the Thermometer denotes
the freezing point, and 55 temperate. In Barometers
fair is usually placed opposite 30, and rain at 29.

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