result.

THE WELSBACH GAS LIGHT.

In the mean time, however, while electricity for lighting purposes has,
to say the least, not made any startling advances, we have, besides the
regenerative lamps before mentioned, the new Welsbach light, which is
exhibited before you to-day, by the kindness of Dr. Wallace; and if the
results said to be obtained by it are at all what they are represented
to be, we certainly have a new departure in gas lighting of no mean
order. Dr. Wallace--a gentleman who is well known to us as one well
qualified to test its merits--has found that the Welsbach burner
produces a light equal to more than 9 candles per cubic foot of gas of
25 candle power, thus nearly doubling the amount of light compared with
gas consumed in the ordinary way.

The construction and manufacture of the burner I have seen described in
these terms: Chemists have been diligently working for many years on the
problem of how to convert into light the highly condensed heat of the
Bunsen burner; and a Vienna chemist now claims to have solved it.

The first condition of the problem was to find a medium on which the
heat could be perfectly concentrated and raised to illuminating power.
Many experiments have been made with platinum in a Bunsen flame, and a
brilliant enough light has been produced, but at a cost altogether
outside commercial use. The Vienna chemist, Dr. Welsbach, has discovered
a composition which is as good a non-conductor--that is to say
concentrator--of heat as platinum, is much more durable, and a great
deal cheaper. The base of it is a peculiar clay, found in Ceylon, which
combines the indestructibility of asbestos with the non-conducting
property of platinum; and having found the incandescent medium, he has
next adapted it to the Bunsen burner.

In this arrangement there is the simplicity of genius. He gets a fine
cotton fabric woven into the shape of a cylinder, with a tapering point.
In its first stage it is about 2 inches in diameter; and after being
coated with the composition, it is subjected to a strong heat. This has
two effects--first, the cotton fiber is completely burned out, while the
composition retains the shape of the woven surface on which it was
moulded. Then the cylinder contracts and solidifies until it becomes
about the size of the forefinger of a glove. Dr. Welsbach calls this his
"mantle;" and by a simple arrangement he fits it on a Bunsen burner, and
places an ordinary lamp chimney