New-York tribune., 1878-07-20
SCIENCE FOR THE PEOPLE.


OYSTER CULTURE IN CHINA.-Like so many
ether peculiar things the Celestil Empire the CHI
nese system Of oyster cuture differs widely from that Oh
Europe OF America. In the southern parts OF emma
"coectors Of bamboo are placed IN the oyster beds,
much after the same fashion the elaborate tiles and
a hives" employed in France. These bamboo oyster
oatchers however, are prepared in curious manner.
The exposed for about two months TO the rays
Of SUM- and then placed for the same period IN sat
water after which they again dried for several days
NOtches are then cut In the canes, into Whoh empty
oyster shells are fixed. and thus prepared they are
driven into the seashoFe between high and low water
mark ana left standing catch the young oyster spat
Those localities are considered the best where the
rise and fall Of the tide tho greatest, so that the b
valves may alternately covered by the flood and ex
posed to the air on ebb tide Aiarge trade is carried on
by these collectors and successful oyster cultursts are
known 10 have amassed considerable fortunes. The
young oysters seem to develop very rapidly and are
ready for market when old Large quant-
state For this purpose they are taken from ths
shells simply plunged into boiling water ana p 0 @
till every particle Of moisture has eYaporatea 1ne5
The doest nd latest oysters bred and Sattened the
bamboo eulcb are selected for aier tnis
method those taken from the natural bed beng uerOr
in quality. and not sufficiently fat to endure the
operation.
CURIOUS ASTRONOMICAL PHENoMENON.-The
Pitsburg Chronicle records singular phenomenon con-
neced with the planet jupiter seen by Messrs Gem
and Wampler OF MeKeesp0r Penn on the night OF the
l1th lns with venoh telescope At 1905 D. m these
observers noticed the eastern margin OF the disc oil
Jupiter dark round spot just above the northern belt
IL soon moved rapidly westward just touching the belt
and parallel with Jupiter equator, and passed on the
face of the planet 124 Of the 18th. Its appear
auce while passing the disc OF Jupiter that OF
perfect sphere globe much larger than any Of Ju-
pters satellites It appeared stand out in space be-
tween the planet and the observer we'll and sharply
Defined and most intensely black 1t reflected no light,
and was either before ers passage across
the planet 1t could not have been spot on the globe
of Jupiter for passed over It's disc from hS internal
contact last external contact OF marns IN three h0us
and nineteen minutes, whereas sPo would nave aEeR
q because all the four satellites were & IN @ bss yew
other observers witnessed this curious transit
A New GUN-CoTToN.-A modification of
Roncotton known tonite cotton powder Is said TO
possess peculiar properties Ordinary guncoton OF gun
cotton waste STEPPED in nitric acid and left in moist
state 70 dsinteRrate passed between neavy rollers and
then subjected frequent washinR Tonlte consists OF
this macerated guncottOn intimately mixed up between
edgerunners with about the same weight OF nitrate OF
bSryta The compound then compressed into candle
shaped cartridges formed with recess at one end Tor
the reception OF a illuminate Of mercury detOnator'
Among the advantages said to result from the use OF the
nitrate are that It contains great amount OF oxygen in
small volumes that Il is very ready under the detona-
tor while its great density makes It slow 60 the infu
ence Of ordinary combustion. By the employment Of
nitrate Of baryta claimed that this explosive can
not merely be made much cheaper than ordinary gun
cotton but that the same weight Is about ~ per cent
Htronger It may Incredible, but tonite cartridge
IA no more liable TO catch fire than piece OF soap, Whicn
Il resembles; its great density causes u 10 Dufn slowly
Generation Of gases Is obvated The tOnlte cartridges
generally waerproOfed Tue density Is sncn that ~
takes up the space dynamite ana tWOthrds That
OF gun-cOtton.
PREVENTING THE FOULUNG OF IRON SHIPS
One of the Disadvantages connected with the Of iron
shps has been the extent to which such vessels foul
become covered with marine ncrustations ON long
ages especially in tropical climates 1t has been esti-
mated that IN the of sailingships this fouling
causes an average difference Of from one to ono and
half knots an between the speed maintained the
outward voyage and that when coming home. Ii is true
that foumg could be prevented by fret covering the
iron with layer Of wood, and sheathng this with cop
per- but the process is very costly 1t now claimed
that by the Of paper this puzzng problem has been
solved kind OF paper cement has been discovered,
and tried with encouraging results on the English war
steamer serapis In addition TO a trip India and
back the vessel had lam in harbor for two mOnthsa
much seyerer test for a1tifouliDg composition than
ocean sang-bu being dOcked II was found that the
paper had afforded perfect protection nom marine IN
rubbed OH The composition OF the cement is sthl Kept
secret.
A NEW AMERICAN BUzzARD.-Mr. George b.
sennet, Of Erie PENN and Dr. James Merrill u s. A,
have Just discovered Texas specimens OF new Amer
ican buzzard which the Smithsonian authorities have
identified as Biteo abosaudaLs large and handsome
hawk very different from any hitherto known 10 occur
in the United States Both the above gentlemen arc
jealous and successful orntholOgists, aud Dr. Elliott
COues who sends particulars Of their discoveries
TO The Coury adds that the importance Of the eOntr
buttons made by them may 6o lnierfsd from Ine Iacs
addition Of about twenty species and several genera 10
the list Of United States birds