The morning call., 1894-01-14
SCIENTIFIC NOTES.

In the use of mixed gases for lantern pur-
poses the question sometimes arises as to
whether coal gas or pure hydrogen Is most
readily exploded in case of rise Of tempera-
ture. An important contribution to our knowl-
edge has recently been made BY Professor VIC
tor Meyer. 1t was found that with pure by
drogen and oxygen the initial temperature
required to cause explosion varied between 612
deg. and $50 deg, no difference being found
whether the gases be dry or moist. The pres
ence OF platinum foil prevented explosion,
quick combustion always took place even when
a temperature of 715 deg. was reached. When
hydrocarbons were used with oxygen lt was
found that the temperature needed 10 lnduce eX-
plosIon was lower the greater amount OF carbon
present. Thus the mean temperatures of explo-
slons with methane. ethane and propane were
657 deg. 616 deg and 547 deg. respectively.
Ii Will thus be seen that whatever the difference
may amount to in practice IL is TACT that pure
hydrogen and oxygen VIII be more difficult TO
explode than mixtures OF coal gas aud oxygen.
DIR. Langley of the Smlthsonian Institution
advances a new theory as TO the nature OF
wind which he thinks goes long way toward
determining the ultimate possibility of me-
cbanical flight. The wind is Dot, the doctor
says, even an approximately uniform moving
mass OF air, but consists Of succession of
very brief pulsations, varying in amplitude
and, relatively to the mean movement OF the
wind in direction also. Once launched into
the mean velocity OF the wind flying machine,
therefore, If 1t had the power to vary its 1ncl-
nation, could take advantage OF the varying
velocity and direction of the wind. Falling
with the slower wind Ii would accumulate the
energy which 1t would have 10 expend in ris-
ing with the higher, and thus become capable
of indefinite sustainment or advance. 1t would
require, however an even more intimate
,f1fOL Of fhn
rents of th air than mariner possesses as to
the currents of the sea,
A new automatic system OF lighting and ex-
tinguishing street gas lamps has been invented,
says the Scientific American. Each lamp is
supplied with two Sal-ammoniac batteries and
a spark coil. placed in all iron box buried in the
ground at the foot of the post In the lantern
Is miniature gashOlder of about two cubic
inches capacity. pivoted on hinge and held
down by weights, and directly over this holder
is an automatic gaslighter. Two wires connect
the lighter and the batteries. When II Is de-
sired to light the lamps of city 1t is only neces-
sary to open the valve connecting one Of the
large gasholders at the WORKS direct with the
gas main. This increases the gas pressure all
over the city and causes the gasholders in the
lamps to lift up against platinum stop and
thus close the local battery circuit at each
point. The automatic lighter is by this means
supplied with current and turns on and ligh is
the gas. The repeating of the same operation
will extinguish the lights.
Two Holland inventors have devised method
for sterilzing milk by the aid of the electric
current. There have been brought forward re-
Gently many proposals TO steriZe water in this
way, but milk has proved much more difficult
huld, because OF the large amount of pabulum
for cTo-organism which it contains The
milk TO be sterlliZed is submitted to the action
oil strong alternating current, which Is ap-
piled TO the milk in ordinary dairy utensils.
Inc process may. however, be worked contlnu-
ousy by passing the milk at suitable rate
through narrow trough. fitted with series OF
metallic plates conn ected with the poles OF the
source of electricity. 1t is claimed that by this
method all microbes that may be present ln the
milk, whether derived from the air. the cans, or
diseased cows, are destroyed, and that the Iish
of transmitting infectious maladies through 'his
medium is obviated.
The volcano Ell Calbuco, In the AnoeS, mas
renewed its activity. says recent Dumoer Vi
Nature. after having remained dormant during
all the memory of man. Some months ago
columns of yapor began TO issue from the
crater. their escape being accompanied by the
usual subterrapean noises, seismic movements
| and elecIrical phenomena. This stage was fol-
| lowed nv the election Of sc0rlal and rock frag-
ments which burned up the surrounding
| woods and raised the temperature OF the
| erouud to a high state. AT the present time