The record-union., 1899-02-27
SCIENTIFIC KNOWLEDGE.
.REcoRD-UNIoNn NOTES OF
DISCOVERY.
Arc-Light Telephone-The Plague
Lightning Rods-Oil for Roads
Color Of Water.

AASnCn10& ktooS-O1l Tor kSO30A
Color Of Water.
The arc lamp as a telephone, although
we'll within the range of the possible, is
as yet but little practiced, says
IL Electrician" Paris), as translated in
The Electrical Review" The flame OF
the arc lamp is very sensitive, and Is
affected by the feeble variations pro-
duced in neighboring circuit trav-
ersed by an alternating current. II
microphone is inserted in this neigh
boring circuit, the arc will reproduce
with great fidelity the different SOUNDS
and noises by which the microphone IS
affected. In the same way, sound re-
ceived by the arc will produce in Its
circuit a modification in the resistance
and a variation in the current, effects
which would affect telephone. The
arc lamp can then be utilized with as
much facility as a telephone transmit
ter as a receiver. These results are
very easily obtained, but it would be
Well to remember when telephoning in
this manner, to protect the eyes with
smoked glasses.
Speaking of the persistence of the
cc1ttagion of the plague microbe, which
is causing SO much anxiety in Austria
and Germany, the journal La Suisse
Geneva) cites a characteristic case.
'In 1860 the Dutch city of HARLEM was
devastated by the plague. Whole fam
lies persisted, among them a family by
the name of Cloux, whose various MEM
bers were buried in the HARLEM
church. Thirty or forty years ago it
was found that the masonry of the
tomb was out of repair, and the vault
was entirely rebuilt. The masons in
charge of the work descended into the
vault and remained there during more
than day. Now, although more than
two centuries had passed since the ep-
idemic, all these workmen were at
tackled with the infectious bubo Char
acteristic glandular swelling) of the
plague, and had to undergo long treat
ment at the hospital. Nevertheless.
there were no symptoms of the plague
proper, and all recovered
zone of the best evidences of the
value of lightning rods up to date" says
the Scientific American Supplement"
has been afforded by the Washington
monument. It is capped by a small
four sided pyramid of aluminium, which
metal, so cheap to-day, was very costly
at the time of the building of the
greatest obelisk that the world has ever
known. This aluminium tip is connected
with the ground with four copper rods
which go down deep into the earth. On
April 8, 1885, the monument was struck
fiercely five times, but it suffered no
damage whatever. On June 18th of the
same year a. more tremendous assault
was made upon the monument from the
heavens, and the result was q fracture
of one of the topmost stones. The crack
still remains to show what nature can
do in the way of an electrical shock,
but the slightness of the damage is evil
dence OF mans power to protect him
self from such attacks. The obelisk is
ideally located for attracting electrical
assaults from the skies, and yet, while
many times hit, it has suffered only
once, and that time to trifing extent.
The statue of Liberty, New York har-
Dor. is protected by copper rods united
t. the figure and extending through the
pedestal to copper plates buried in wet
ground beneath the foundation. Light
ming has never injured the statue in the
s least"
The Doctor Carl Peters" says the
Engineering and Mining Journal"
translating from L'Electrochemie,"
the boat which carries the name of the
German explorer, and which is destined
for Lake Victoria Nyanza, in Africa,
has made a tour of the Lake of Zurich
with the engineers of the makers,
fischer Wyss & Co., and invited guests
on board. This boat which had it's
trial trip on July Goth, in presence of
German commissioners delegated by
the Minister of the Navy, is of alum
mum. The conditions of the contract
prescribed that no single part of the
beat should weigh over 16O Kilograms
Coz pounds), and this condition could
not be fulfilled with any other metal
The boat is 10 meters (43 feeD long
"a meters g feeD wide, and 1.45 me-
ters @ feeD deep 1t may be detached
into nine separate sections. The two
boilers are Independent OF each other.
and are for burning only wood. The
boat can carry fifty persons. In a short
time it IS to be taken apart, packed in
cases, and sent to the east coast of
Africa. There they will be received by
caravan of negroes, escorted by troops
Of the protectorate, and transported
into the interior. 1t is estimated that
this transport column will take four
months to reach Victoria Nyanza. The
Doctor Carl Peters makes about sixteen
kilometers (ten miles, an hour, and
the engine runs at the high speed of
$50 revolutions per minute. The cost
of the boat is. in round figures, $4,000.
At the recent Good Roads Convention
in ST. Louis a civil engineer of Keokuk.
ia, reported that he had obtained ex-
cellent results with crude oil in i'm
proving the condition of highways. and
recommended wide experimentation
with the system. His attention was
first directed to the use of oil by read
ing in a Pennsylvania paper that oil
from a leaking pipe had dried up a
spot in the read that was nearly i'm
passable in wet weather. According
to the story, the ground became sat
urated with the oil, and soon it was
noticed that the mud dried up and the