The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1858-05-10
sc 1ENCE AND ART

NEW system OF MoULDIYG-There has been re-
Gently communicated to the French Academy of
sciences, new system of moulding, which gives
10 plaster the hardness and durability of marble.
The inventor of this process places the plaster In
drum turning horizontally on its axis; and admits
steam from steam boiler. BY this means the plas,
ter is made to absorb in short time the desired
quantity of moisture, which can be regulated with
the greatest precision. With plaster thus pre-
pared, and which always preserves Its pulveru-
lent state, suitable mOuds are filled, and the
whole is then submitted for short time TO the
action of a hydraulic press; when taken out
of the moulds the articles are ready for USE
This process is simple and economical, the cost
of the manufacture very little exceeding that of the
material. The plaster thus prepared is perfectly
hard and compact, taking the polish of marble; the
most delicate bas-reliefs and highly finished medals
may be produced from it, with the same degree of
artistic perfection as characterizes the original. 1t
is also found, after experience of several wears
that productions obtained by this process resist the
most unfavorable atmospheric influences; and pos
sassng this property, it can be employed as well for
works in the open air as for the interior of build
ings. 1t is proposed to substitute this substance
for all ornamental purposes where marble or stone
has been hitherto employed, and from calculations
which have been made it is believed the cost of the
article will be much below that of cut stone of the
first quality.
MAGNETIC PHENoMENA.-Professor Hansteen, of
Chirstiania, the eminent magnetical philosopher
has presented memoir to the Swedish Academy
proving from his own observations, that the mag
netic dip partakes of the daily, annual and eleven
yearly periodical changes-the last coinciding with
which have been already detected in the other
magnetic elements. The same distinguished phi
losopher, who is now in his seventy third year.
expects soon to complete the reduction and
publication OF the magnetical results of his
Siberian journey, in the years 1S2S-'30, which
have long been desired by the scientific
world. Another interesting theory in the range
OF this department of science, is that propounded
and nn1xt oh h..
yorably noticed by the British Association of Sci
ence. This theory of Mr.. Drummond starts from
the generally received hypothesis that the earth
has cooled from molten to solid state, and as
sumes the existence, within an external crust con-
shutting the earth's surface, of fluid nucleus aei-
tated by system of internal tides similar to those
OF the ocean, and also of mountainous inequalities
upon the inner surface of the crust. The internal
agltations of the fluid nucleus, according to the
theory maintained by Mr.. Drummond are to be ac-
counted as the cause of the earthquakes and voca-
mic and magnetic phenomena on the exterior of the
earth.
ENCLOSING WooD.-Raised figures upon wood,
such as are employed in picture frames and other
articles OF ornamental cabinet work, have usually
been produced by means of carving, by casting
the pattern in plaster of Paris, other
composition, and then cementing or otherwise fix
ing 1t on the surface of the wood. The former
mode is expensive, while the latter is inapplicable
on many occasions. An invention which meets the
want of the artist in this kind of work has come
into use, the principle mode of action involved
being, that if depression be made by blunt in
strument the surface of the wood, such
depressed part will again rise to its original
level by subsequent immersion in the water
The wood is to be ornamented, having been first
worked out to its proposed shape, is in state to
receive the drawing of the pattern; this being put
on, blunt steel tool or burnisher, or die, IS APP
piled successfully to all those parts of the pattern
intended to be in relief and at the same timeis
driven very cautiously, without breaking the grain
of the wood, till the depth of the depression is
equal to the intended prominence of the figures
The ground is then reduced by planning or filing
to the level of the depressed part; after which, the
piece of wood being placed in water, either hot or
cold, the part previously depressed will rise to its
former height, and will then form an embossed pat
tern, which is finished by the usual operations of
carving.