Courier Democrat. (Langdon, N.D.) 1891-1920, 1894-01-04
SCIENCE ANU INDUSTRY.
USEFUL INFORMATION FOR THE
CURIOUS. 3.
Musical Analy sis OF Gnses-The New
French Battle ship-Electricity ia
sugar RcfininE-A Light That Fall
ell-Science Notes. fiS

The eminent French scientist, CASTOR
Tissandier, describes an absolutely new
method of determining the quantity d
foreign gas contained in air by the pass.
ing of the gaseous mixture through SON
orous tubes. The invention is credited
to M. Il. Hardy, distinguished French
physician, who calls it the ''formene-
phone" and intends it primarily for the
detection Of fire-damp in mines. Varl-
GUS. scientific apparatus have been de-
vised for this purpose, but few nave
turned out to be practical. One OF
these is the tire-damp meteor Of M. Co
quillion, perfected by NJ. Grehaut. This
certainly measures the quantity of gas
in the air, but is too delicate for the
wear and tear of mining work. One Of
the best indicators of gas yet known Is
the safety lamp, in which the presence
of the dangerous fumes Is made mani
fest by the appearance Of an auroele
around the flame of the lamp. The
radical objection to this method Of de-
lection is that the aureole doesnot show
itself until such a quality of gas Is
present as constitutes critical danger.
The fOrmenephOne, on the contrary,
gives the indications in few seconds.
The principle on which it is based Is
that when two organ tubes giving the
same pitch are subjected to the influ-
ence of two equal blasts Of pure air the
sound produced is identical. But, every
thing else being equal, If one OF the
tubes is blown into by mixture OF air
and gas of different density, the sound
of the tube is correspondingly modified,
and the vibrations produced are more
or less frequent as more or less gas IS
mixed with the air. This occurs with
such unvarying results that M. Hardy
has been able to lay down regular
scale of vibrations and their signltl-
canoe for the guidance Of those using
his invention. The apparatus consists,
briefly of two blowers, Oh pair OF bel
lows, inclosed in alright metallic en-
velopes. One of these cases contains
pure air only, and to the other is con
Quoted by pipe the air OF part OF the
nnne to be tested. The air IN each re-
ceptacle is blown by the Arrangement
Of weight on the top OF the bellows,
whereby downward and forclDle pres
sure is Immediately produced, into the
organ tube with which each receptacle
is provided. The resultant sound is so
intensified by a special adoption OF the
microphone and the telephone. that II
Can be distinctly discerned, and com.
parison of the difference in sound of
the two tubes gives an absolute indica-
ton of the quantity of gas in the air
tested. In order to secure greater precis
ion in the record of this indication, a
register is provided Oh which the num-
Der of beats given per second is mark
ed, so that all chances Of inexactitude
are eliminated. While this Invention is
designed mainly for use IN mines, IT Is
mixture Of air and any gas not having
the same density, and especially mix
ture of air and carbonic ac4l. Installed
in a room of ordinary dimensions, il
will tell exactly to what extent the all
has been vitiated by the presence Of
4 one or more persons in a given time.