The Cook County herald. [volume] (Grand Marais, Minn.) 1893-1909, 1894-09-08
SCIENTIFIC MATTERS.
sOME NEW WRINKLES OF CLEVER
GENIUSES. -,
War Departments Interested in the
Subject OF Signaling From Ball.
loons-Preserving Books In the
Tropics. ~.


seen from large tracts Of surrounding
country have been repeatedly proposed,
and have attracted fair share Of at
tention. The dangers of lights on gas
balloons, however, and the bulkiness Of
air balloons in which gas explosion
dangers would be absent, proved seri-
GUS obstacles to be overcome, and it
was not until the electric incandescent
lanp had been successfully developed
that there seemed any great promise
OF being able to practically accomplish
much in this branch of signaling. With
the incandescent lamp, of course, fire
and explosion risk was reduced to q
minimum, and it was fully demonstrate
ed by experiment more than a dozen
years ago that with the then cOmpara-
lively new light it would be easily pos
sible to flash messages from balloons
backward and forward across country
at night In a most satisfactory manner.
For war purposes the value Of such q
system at once commended itself, and
the idea was speedily worked out to a
very encouraging degree, at least in:
England, where a London inventor for
a time regularly exhibited his electric
signaling balloon in operation. The bal
loon, as it is now remembered, was
about twenty feet in diameter, and was
allowed to ascend to height Of about
500 feet, being rendered visible by six
fncandescent lamps Of twenty candle
power each, fed from a battery on the
ground. The material Of the balloon
was translucent cambric, and when
the lamps were burning the whole
glowed with a soft light, which was
decidedly noticeable and in a clear
atmosphere could be seen for miles
around. In the conductors from the
battery to the balloon was inserted a
Morse key by which the circuit could
be made and broken. and the lamps
be caused to give long and short flashes,
corresponding to the dashes and dots
Of the telegraph code. The whole ar
rangement recalled, Of course, the time
honcred heliograph and the electric
light signaling devices used aboard
men-of-war, but at the same time 1t of
fered advantages over both. It could,
clearly, be used in a fiat country, or
between valleys separated by low hills,
instead Of being confined to elevated
points like the heliograph. The balloon
also showed "a large illuminated dis4
:" pIdCS= VI luS S1ldl ulAlIOI,
and could be packed, together with its
batteries, into little space for transport
More recently this form 1T balloon
seems to have found favor with the
Italian war department, and it is not
unlikely, therefore, that more will be
heard Of 1t in the near future.
Magazine.
Preserving 9,ooks in the Tropics.
The task Of the librarian in hot eli
mates is beset with anxiety. In addi-
ton to the cosmopolitan book-maggot,
which drills pin-holes through and
through the cover and body Of the
book, and often completely disinter-
CRATES it, he has to fight various kinds
of ants and cockroaches. The white
ant for instance, devours the books
wholesale, but can generally be thwart-
ed by placing the shelves upon stone
insulators. The cockroach is Of less
Importance, as it merely defaces the
bindings. The usual protective treat
ment is to disinfect the book by pour
ing few teaspoonfuls of refined min
eral naphtha, or benZine into the crev-
ices OF the bindings, and then shutting
up the volume for a few days in a
close-ftting box to prevent the escape
Of the fumes. If the books are sub
sequently sponged over lightly with
the finest kerosene oil, which is rubbed
OF With q cloth before it has time to
penetrate into the binding, they are
rendered distasteful to insects without
causing serious injury. The odor Of
the Kerosene is Objectionable, but COM
unit S7~Nr,
is secured. DR.. George King reports
favorably on an improved method.
which consists in brushing the books
over with a saturated solution Of corro-
sive sublimate, made by constantly
keeping a few humps of the poison at
the bottom Of the jar Of alcohol (the
ordinary methylated spirit, so that the
maximum amount may be absorbed.
1t is needless to state that the poison
must be very carefully handled. In
the Indian Museum Library the
amount OF damage is greatly reduced
by keeping the books in close-fitting
glass cases, on the shelves of which
are placed few ounces Of nephthaline.
AS an additional precaution the paste
used in binding the Indian Museum
books is poisoned by adding about half
an ounce Of sulphate Of copper to each
pound of paste. Books already infest-
ed are shut up for four or five days in
an alright box Of loose naphthaline
with as much of this substance as pos
sible between the leaves. This treat
ment efectually disposes of even the
'sduck ant" one of the most destructive
pests Of the tropics. IF this insect
once enters a book he rapidly turns
every page into the most elaborate lace
work. s.,t
Efficiency of the Modern Soldier.
Great attention is being paid by Euro
pean military authorities to methods Of
facilitating the passage Of rivers by
cavalry. For this purpose a bag which
has been designed by Russian officer
is expected to be Of Immense service.
It is made Of waterproof canvas,
weighs only 21-2 pounds, and Is 4