The Donaldsonville chief. [volume] (Donaldsonville, La.) 1871-current, 1882-12-16
SCIENTIFIC MISCELLANY.

often appeared so differently in different
parts Of the country rs to make him
doubt their identity until after close
examination. This was particularly true
of coniferous trees.
Water issuing from hydraulic pipes
exert an astonishing erosive power. IN
one hydraulic mine pebble loaded
stream working eight months in year
has in four years cut q channel in solid
slate rock three feet wide and fifty feet
deep-according to Packard.
Herr S. Wolff endeavors to account for
sun-spots by a new theory. He thinks
they may represent areas on the san that
are vastly hotter than the bright surface
surrounding, instead of being cooler as
astronomers generally believe. They are
regions SO extremely hot, lie supposes,
that the heat radiations have reached
the intensity Of ultra violet [red rays;
these being invisible the spots consc-
quently appear dark.
| A novel and remarkable thermo-chem-
ical battery has been produced by Mons.
Brard of LII Rochelle, which he regards
as solution Of the difficulties ex-
perienced in getting an efficient electric
current from heat. The battery consists
essentially of slabs of prepared carbon
containing nitrate of potash. When
these are burned u continuous current is
generated until thsyare consumed. A
slab six inches long, }so inches wide and
All inch thick lasts aq.hour and a half OF
two hours, aud Will ring an ordinary
electric bell; and three or four slabs
connected to increase tension will decom-
pose water.
Archmologists know that ropes date
from very remote period, and had
reached a state of considerable perfection
at the dawn of the historical era. The
FIRST ropes were probsbly made FROM the
fibres of tho inner bark of trees, from
grasses, or from tho. hides of animals.
Among tic relics ofthe ancient Egyp-
tians have been found sculptures show
ing the process Of rope-manufactnre
practised more than 1000 years ago, while
the oldest records of that people repre-
sent we'll made ropes capable of sustain
ing enormous burdens. 1t appears that
flax and the fibrcs Of tho date tree were
employed for those ropes.
1t is proposed to place the islands of
Mauritius and Reunion in communication
with each other by means Of an "optical
telegraph" Tho stations will be about
l34 miles apart, and win occupy an
eley1sed spot OH seach island. From
ssa will, " the aita-of
a petroleum lamp, be flashed across the
intervening stretch of the Indian Ocean
to the opposite station, where they will
be received by telescopio apparatus
which it is prodosed to arrange 90 us to
photograph the luminous flashes. If
successful, this system of signaling is
expected to prove of especial value in
sending warnings Of tho approach of
cyclones. .=-.
During the French invasion of Mexico
plant was discovered which was found
to possess tho property-when cEewed or
crnshed-of stopping hsmorrhages. To
the native Mexicans this plant was
known by name which may be rendered
az fowlwort" The discoverer carried
y specimen to Versailles and planted it
in 1867, and it has since fourisl,ed,
lowered and fraitod without apparent
change in its peculiar qualities. The
action of this plant is said to exceed that
Of all styptics known, and this valuable
property is likely to give it wider
extension, especially as it seems to be SO
readily acclimated in foreign lands. It's
botanical name is 1radescantia erccta
(Jacq.).
Speaking of waste" favorite theme,
DR.. Siemens lately said that he had been
experimenting at his farm at Tunbrilge
Wells with the object of utilizing to the
fullest possible extent tho heat applied
to a steam engine. His engine drives a
dynamo-electric machine, which not only
lights his greenhouses at night, but also
furnishes artificial sun-enabling him to
rapidly grow fruit in tho depth of winter
Nor is this all, for the escaping steam
from tho engine is made to heat the
greenhouses and other places in winter
10 that hs expends but little more fne
since he started the electric light anl
dynamo machine than he did before in
heating those houses.
, Since lS43 Oh average Of SIS earth
quakes year has been known to occur
Mallet has collected tho records of 6S3(
earthquakes which took place over
period of 3455 years previous to 1850
: but 3240 of these occurred during tli
last fifty years. 1t seems, therefore, tia
our earth is almost constantly shakin,
at some point, and no part of the worl,
is entirely free from tremors of SOM
degree. Prof. Milne has recently urge,
that the study of earthquakes shonl,
, receive more attention in countries littl
| subject to their visitat:ons. Such coun
| tries may at long intervals he shaken by
, earthquakes of y severe character, and i
| is suggested that even the stable grount
, of England may not he secure aeaina