[Illustration: FIG. 1.--SCRIVANOW'S CHLORIDE OF SILVER PILE.]

In our opinion, Mr. Scrivanow's pile is not adapted for industrial use
because of the expense of the silver and the frequent manipulations it
requires, but it has the advantage, however, of possessing, along with
its small size and little weight, a disposable energy of from 150,000
to 200,000 kilogrammeters utilizable at the will of the consumer and
securing to him a certain number of applications, either for lighting or
the production of power. It appears to us to be specially destined to
become a rival to the bichromate of potash pile for actuating electric
motors applied to the directing of balloons.--_Revue Industrielle_.

* * * * *




ON THE LUMINOSITY OF FLAME.


The light emitted from burning gases which burn with bright flame is
known to be a secondary phenomenon. It is the solid, or even liquid,
constituents separated out by the high temperature of combustion, and
rendered incandescent, that emit the light rays. Gases, on the other
hand, which produce no glowing solid or liquid particles during
combustion burn throughout with a weakly luminous flame of bluish or
other color, according to the kind of gas. Now, it is common to say,
merely, in explanation of this luminosity, that the gas highly heated in
combustion is self-incandescent. This explanation, however, has not been
experimentally confirmed. Dr Werner Siemens was, therefore, led recently