The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1858-06-02
SCIENCE AND ART,

AN IMPORTANT lNVENTToN.-There has lately been
exhibited in Paris, electric light of unusual bril-
liancy, obtained by the means of lamp of peculiar
construction The objects of this invention are-to
regulate and to keep constant the distance between
the two electrodes of electric lights, whatever NAV
be the rapidtv of combustion of the prapbite of
which they consists to obtain this constant separa-
ton of the clectrodesby selfacting means operating
by the action of the current which produces the
light, combined with the action of SPRING or with
the action of current derived from the LIGHT Cur
rent; also, to obviate the necessity of any daily
regulating of the apparatus.
These results are obtained by the passage of mer-
curry from a reservoir into a receiving cylinder
placed underneath. The tendency of the mercury
to rise in this cylinder lifts with little friction ps-
ton supporting the lower electrode, which an
proaches the upper electrode according as the mer-
curry of the reservoir flows down into the cylinder
The action of the electrodes approaching each 9TH
err is produced by means of a valve opening and
closing the tube communicating from the reservoir
into the cylinder.
This tube passes through one of the soft iron
arms OF an electromagnetic, which receives its mag
netic action from the current producing the light,
and which shuts the valve by its action upon an
armature of soft iron which it presses against the
valve. The armature which shuts the valve by the
action of the current producing the light is attract
ed in an opposite direction by spring, or by a
second electro-magnet receiving magnetic action
from the derived current, the intensity of which is
determined by the resistance offered to it by coil
interposed for that purpose.
MACHINERY FOR MAKING ENvELoPEs.-One of the
most remarkable triumphs of mechanical ingenuity
is the invention of those machines. by which enve-
opes are now manufactured with such amazing
rapdity and exactness. One of the best contriy-
ances is that invented by Mr.. De la Rue. The
operator places diamond-shape piece of paper on
little PLATFORM; a sort of plunger descends, and
forces the central part of the paper into obong
quadranguar cavity; the four corners stand erect,
and these successfully tattened by four levers
fingers, or thumbs, whereby the envelope form is
given.
And when all is done, two India rubber fingers
lightly touch the envelope, and delicatey draw it
aside, to make ready for another. These fingers
are quite refinement of ingenuity-they are small
metallic cylinders, with bits of India rubber at the
lower ends; these fnger-tips have just enough of
the glutinous or sticky quality to adhere slightly to
the paper on which they are pressed, and to draw
1t away from its place ON the machine.
But while these processes have been going on,
there is another series also in operation to effect
the cumming or fastening. There is a supply of
gum which spreads itself over an endless apron or
blanket, and an artificial takes supply of gum
from this blanket to apply it to the envelopes. All
THESE movements are so nicely adjusted, that the
gum is applied in its proper place just before the
flap OF the envelope is folded down.