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 over it. When the flame is applied, the
"mantle" becomes incandescent, and gives out a brilliant yellow light,
which, it may be said without exaggeration, will compare favorably with
any electric light yet put on the market.

For decorative effect a pretty frosted globe is used; and by varying the
globe a pure white or a pure yellow may be obtained. It is also added
that there is no act of Parliament required for it, nor even a
provisional order of the Board of Trade. No streets have to be broken up
in order to lay down pipes; and no wires have to be hung across the
roofs of protesting householders.

The whole apparatus can be got ready to fit on an ordinary gas bracket;
and two or three spare frames with "mantles" can be kept in the house in
case of accident. Whoever sees the Welsbach incandescent light in