The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1897-06-20
SCIENTIFIC.

New discoveries of rocks dangerous to
navigation show no signs of diminishing
not less than 200 rocks and shoals not be-
fore known having been reported to the
British photographer in 1896.
A new X ray tube with adjustable
cathode shows that the exact position of
the cathode enormously affects the penetra-
ton Of the rays, change of third of
an inch giving range of penetratiVe pow
er from the highest almost to none at all.
The surprising theory that whooping
cough is contagious only before the patient
begins to whoop is advanced by DR.. WE'LL
a French physician. From many cases of
exposure he has satisfied himself that all
risk of infection ceases at the beginning of
the whooping stage or very soon after.
1t might puzzle many to say why the
feathers of birds rest closely against the
body, even in the strongest wind. A Ger
man naturalist has made experiments
showing that in the birds flight through
the air the feathers are electrified positive
ly, and the white down negatively causing
an attraction that smooths down the
feathers.
In some late experiments on the bursting
of small fly wheels the first wheel tested
1878 inches in diameter, burst at a speed
of 6525 revolutions per minute, or q rim
speed of over five miles a minute A tim
Der casing around the wheel was complete
ly demolished, and piece of the rim was
pine, and two and half inches into the
hardwood floor.
The scheme of covering the Sahara with
forest is pronounced by NJ. P. Privat-Desch-
mel utterly impracticable, the arid plateaus
being hopeless desert. on a limited scale
however, the Valleys-most of which are IA
Vored with a small amount of waterman
be successfully planted with tamarisk
acacia, eucalyptus and poplar, the last
named tree having Unexpectedly proven the
hn chn
tables and fruit trees may be grown.
Fluorine, remarkable both as the most
active of the chemical elements and as the
only one forming no compound with oxy-
gen, was, with great difficulty, isolated by
Moissan in 1887. Its liquefaction, just an
nounced by Professor Dewar,, adds new
and extraordinary detail to the chemistry
of cold. The gas nquefieS at a tampera-
ture OF 1S5 degrees below zero. cent, and
the product is yellow mobile liquid which
has lost the intense chemical energy and
become entirely inert.
An incandescent lamp of three or four
candle power is used by M. Paul Noel, a
French entomologist, for capturing insects
that swim in ponds at night. The lamp is
connected by wires to a small storage bat
terry on the bank of the pond. weighted by
semi-circle of iron, and placed over net
across. The net is, of course, pack-thread
closed by string. The weighted lamp and
the net are SlONly SUNK IN the water, the
lamp is lighted. and insects, fish, lizards
frogs, tadpoles and larvae of every kind
rush up to it. The string is pulled, quickly
capturing several pounds Of victims.
scorpion carrying a flower is the curl
Gus sight seen not long ago by an Alden
correspondent of Nature The flower was a
large blossom OF what is locally known as
the white-gold mohur tree. and the creature
held it over its back by one claw curling
up it's tail TO assist. The nearest tree from
which the flower could have been obtained
was thirty feet away, with two or three
steps and a low stone parapet intervening
This fact seems to prove that the scorpion
carried the flower through intention.
though whether as concealment, to shield
itself from the bright lamplight. or for
some other purpose. is unknown. Scorpions
are not known to feed on vegetable sub
stances nor to construct nests.
The peat coal now being turned out on
a considerable scale In Norway is made by
the process OF Rosendahl, Norwegian en-
gineer. which consists in heating the peat