Daily inter mountain. [volume] (Butte, Mont.) 1881-1901, 1899-05-20
SCIENCE.

Iron felt, the remarkable insulating
material now being made near. Berlin
and rapidly coming into use in Europe,
is described as consisting essentially of
long and strong woollen fibers which are
impregnated with a by-product of petro-
leum, and then coated with gelatine rem
dered insoluble, and also with rubber, at
te1ward ~vulcanized. The felt is COM
pressed into plates measuring two square
feet and upward, with a thickness of a
third of an inch to two inches. The plates
are very elastic, practically imperishable,
and will sustain a pressure of 10000
pounds per square inch, while their sur
face is SO hard as not to be cut by bolt
heads or iron girders. Aside from its in
sulating properties, the material is valu-
able under rails and heavy machinery
to prevent vibration.
Triboluminescence is a name lately
given to the emission of light without
heat that occurs on crushing certain sub
stances, like sugar. The phenomenon has
! been found by Mr.. VIM. j. Pope to be
| particularly striking in saccharin under
| certain conditions, the bluish-White flash
when the crytals are roken in any way
being noticeable in a well lighted room;
but no light appears when the saccharln
is pure, or when the crystals are pre-
pared in any way except by evaporating
a solution in acetOne, or after the crys-
tails have stood a few weeks. Other sub
stances showing the strange phosphor-
essence are hippuric acid and certain de-
riyatiyes of s%antonin. The cause is still
a mystery, but recent study seems to in
dictate that the light is due to some pc
culiarity of crystalline structure.
The eggs of the English sparrow and
other birds in America prove to be very
variable in color, shape and size, and Mr.
J. w. Jacobs has recorded alterations OF
some kind in 40 species.
Wireless biography is no new thing
We have long had forms Of it, as NJ
Bichat of Nancy stated the other day, in
OPTICAL telegraphy and in ordinary
speech, the former depending on sig
nails flashed by waves Of light and the lat
ter on sound vibrations. The new tele-
graphy simply uses vibrations of anothel
sort-those of electricity. The electric
waves are oscillations set up by e~xciters
and they radiate into space, traversine
walls, wood, ETC., but not metals. Hertz
caught the oscillations on a resonant re-
%ceiver, which, however, was not very
sensitive. Inc wireless IeleSrdpny hrs
attempted by Popoff the Russian in 1895
and by Marconi the Italian in 1896. ha:
been made successful only through ar
apparatus devised in 1890 by Prof. Bran
lly of France, and consisting of a glas:
tube containing metal filings, which arr
placed in circuit with a battery and &
~galvanometer. The battery current blu
slightly affects the galvanometer. on ac
count OF the poor %conduction of the fill
ings. When. however, electric oscilla
tons from a spark discharge-near o.
distant-reach the filings. the conduc
tivity is instantly increased and the gal
vancmeter needle greatly DETECTED. Thi
tube, now generally known as a eco
herer," was first called a "radius-conduc
tor" The transmitter Of NJ. Ducretet,
French instrument maker, consists of
dot-and-dash m~aniuplator, resembling
a Morse key; an interrupter, breaking VI
the current into small currents: an in
duction coil; and an oscillator cause
sparks to appear. The receiver is a co
lherer with a tape recorder. With sucl