success; also as a sizing for thread
previous to weaving textile fabrics. Thus it would seem that this
substance has been used for many purposes, but since its application does
not seem to have been extended to any great degree, the defects here
pointed out in its use as a fire-proofing material perhaps also exist, to
a certain degree, in its other applications. In painting upon glass, for
instance, it is asserted that the brilliancy and finish of ordinary
vitrified colors cannot be obtained.--_Glassware Reporter._

* * * * *

THE JET VENTILATOR.

[Illustration: KORTING'S JET VENTILATOR.]

Messrs. Korting bros., of London, induced by the interest that has been
directed to the separate ventilation of mines in which fire-damp is apt
to form, have adopted for this purpose their jet ventilator. The
instrument, which we illustrate in Fig. 1, has been, we understand,
considerable simplified, and adapted for the special object in view. The
ventilators are worked by compressed air, and are so arranged that,
without stopping their action, the quantity of air they deliver can be
rapidly increased or diminished. This ample power of control has been
arranged for by the special wish of the mining authorities, who wish to
regulate the ventilation according to the development of fire-damp or the
greater or less number of men at work. Under circumstances of this kind
the quantity of air taken into the mine can be changed instantly. The
illustrations, Figs. 2, 3, and 4, show different modes of fixing the jet
ventilator. In Fig. 2, it is arranged to blow the air forward; in Fig. 3,
it is shown exhausting the air; and in Fig. 4, it is represented as
exhausting and blowing simultaneously, the efficiency in each case being
always the same. Any bends in the conduit affect the result to a very
slight degree, and the ventilator may be used with advantage when the
conduit is divided as in Fig. 4, in order to get the fresh air to
different points. The ventilators are easily fixed to the air conduits.
If they are to be connected to zinc air pipes, the pipe is simply slipped
over the point, L. in Fig. 1, and if to wooden conduits the apparatus is
simply put into them, and if no other support is required. Furthermore,
they are so light that it suffices for one man to fix them or change
their position.

Messrs. Korting Bros. advance the following claims for this mode of
ventilating mines: Certainty of acti