He goes no further than to assert that M. du
Motay's process simply supplies us with a
luxurious method of lighting which cannot fail
to be adopted here and there—in large public
establishments, theatres, and hotels—but he
scarcely ventures to believe that it is applicable
in an exclusive manner to the public
service.

We ought also to think of the danger
incurred by the close neighbourhood of a couple
of gases whose mixture is violently explosive.
Escapes of ordinary gas cause accidents enough;
escapes of oxygen and hydrogen together would
considerably multiply the chances of mishap.
Lastly, an escape of pure oxygen might have
disastrous consequences, and cause many a
smouldering spark to become a devastating
fire.

Moreover, the magnesia cylinders wear up
quickly; they have to be renewed at least once
a week. We thus make a return, in a roundabout
way, to the troublesome wick of our old-
fashioned oil lamps. The inconvenience, though
trifling in a private household, is serious when
it extends to public lighting. The apertures
which deliver the oxygen in the burners are
much smaller than those for the hydrogen;
hence arises considerable friction and the
consequent necessity for increasing the pressure
for forcing gas through tubes which may be
several miles in length. Employed, however,
as portable gas, oxygen may take an immediate
part in domestic lighting. Experimental lamps,
tried at the Tuileries by the Emperor's order,
have been crowned with complete success.

While the experiments at the Hôtel-de-Ville
were being organised, M. Bourbouze, a gentleman
attached to the Faculty of Sciences, was
making essays which promise not less
important results than M. du Motay's invention.
The result obtained will bear comparison with
the Drummond light, while the mode of
production is much more simple. M. Bourbouze
does not employ pure oxygen; he consequently
avoids the dangers and inconveniences of the
other system.

We have already stated that the intensity of
a light depends on the activity of the combustion,
on the quantity of oxygen supplied, and
the quickness of the jet. M. Bourbouze,
instead of supplying the flame with pure oxygen,
subdivides the combustible into fine threads,
bathes it in a great quantity of air, and wire-
draws it, as it were, by means of air swiftly
urged through holes of small diameter. He
thus obtains effects analogous to those produced
by the combustion of pure oxygen.

His process is this. He causes ordinary gas
and air to enter a close vessel. The mixture
thus obtained, passing through a plate pierced
with a great number of holes, is subdivided into
a multitude of little jets. These jets reach the
under surface of a piece of cloth made of
platina wire, and are not set fire to till they have
traversed the cloth. The metallic tissue is not
of the ordinary pattern, it having been found
preferable to substitute for a cloth, properly so
called, a veritable crochet stitch. This cloth
(like the stick of magnesia in the Drummond
light) under the influence of heat, becomes first
red, and then white, finally emitting a dazzling
light. In order to drive the mixture through
the little holes, recourse is had to a pressure
equal to a column of mercury thirty-two inches
high. M. Bourbouze estimates the economy
of his system to be at least fifteen per cent.

Be it remarked here that the metallic cloth
prevents all danger of explosion, and protects
the detonating mixture from the burning flame,
exactly as the wire-cloth in Davy's lamp keeps
the light within it from setting fire to the fire-
damp without.

IN THE INDIAN ARCHIPELAGO.

AWAY in the Ear East, dividing the Indian
from the Pacific Ocean, and making a chain of
volcanic islands between China and Australia, lies
the great Asiatic Archipelago. European energy
and enterprise have done something with these
islands—to wit, Borneo, Java, and Sumatra—
but more remains to be accomplished; and it
is to be hoped that the Anglo-Saxon hand will
make its mark felt before any other can take
its place.

The most extensive volcanic band in the world
runs through the Archipelago, taking a part of
Sumatra, all Java, and the chain of islands to
the east of it, most of the Moluccas or the
Clove Islands, a small part of Celebes, and
much of the Philippines. There are nearly
fifty volcanoes in active operation, besides
numbers which have become extinct. In 1815
there was a tremendous eruption from the
Tomboro mountain in Sumbawa, the fifth island of
the Sunda chain, which is said to have destroyed
twelve thousand people; but there are continual
outbursts from all the working volcanoes, which
keep the inhabitants in a lively state of alarm.
The more civilised inhabitants of this island
of Sumbawa are the Mohammedans; but the
mountaineers are what they always were;
though the followers of the prophet try to
convert them to the true faith by going through
their villages with whips and rods in their
hands, crying out, "Dogs! do you wish to pray
or not?"

Those who profess themselves converted wear
a scrap of cotton handkerchief on their heads,
eat pork only in secret, and build their houses
after the pattern of the inhabitants of the plain.
But they put their confidence in their stone
idols just the same as before, and the inner man
is untouched though the public faith may be
altered.

Going back to volcanoes, there is a most
singular volcanic phenomenon in Grobogan. This is
a perfectly level and circular mass of black mud,
about sixteen feet in diameter, and situated in
the centre of the limestone district, which
every two or three, or sometimes four or five,
seconds rises to the height of about twenty or
thirty feet, then explodes with a dull noise, and