The sun., 1893-07-23
VOTES ON SCIENCE AND 1xDUyrR1.

served. What Ia fsmiiarly known as Her
| cules powder will. It appears. frecze Mt AZ
Fahrenheit and must be thawed out before
using II frozen, not by roasting It before n hot
fire. nor In any vessel over hot iron plates. nor
| by leaning 1t up against hot brickwork, steam
boilers. or putting It into the oven or in
hot water to thaw. The best way to thaw
tho powder ia found to be to place
SUFFICIENT cartridges for the day on shelf in
the top OF warm room, then put them in tin
| or copper can, and set that inside OF another
hs WHOLE s9nf and naGs H
thawcd. 1t should not be heated to more than
2i2,: Tor soon after that It throws IN no.ious
In q dry. cool. and wel-ventiatc warehouse.
and, when SO stored. 1t will remain In good
| Get on fire in any ordinary way IL burns away
by slow combustion producing moro noxious
gases than when explosion ensucs.
1t seems that the hollow OF the Atlantic Ia
not strictly basin whose depth increases
regularly toward the centre the latest inves-
LEGATIONS showing that 1t is rather saucer or
dish-llke one. so even is tho contour OF it's bed.
II is found that. proceeding westward from
tho Irish coast. the ocean bed deepens very
gradualy-in fact for the first two hundred
and thirty miles the gradient is but six feet to
the mile, though In the next twenty miles the
Fall Is more than nine thousand feet so pre-
cipltous being this sudden descent that. in
many places. depths OF twelve hundred to six
teen hundred fathoms are encountered in very
se CLOSE proximity Ir to the one. hundred -iathom
thousand fathoms. the sea bel in this part Of
the Atlantic becomes slightly nndulat-
tn ns hut hnse o s Ght as
twelve hundred miles: the extraordinary fiat
ness OF these submarine prairies, therefore.
inapproprate. The greatest DEPTH 'n in the f"'. At
lantlc is claimed to have been found some one
Of st. Thomas. where sonndinSs OF cf 'ss4s s.s7s
fathoms were obtained. The seas around
GFra. pr,.n instead Of forming ra,t 2, tho
garded. are now alleged to be rather part of
the platform banks OF the great European con-
tinent which the ocean has overflowed.
In the microscopical research Of metals a
most important factor is the character OF the
polishing powder EN- poyed for the specimens.
and this desideratum Is now said to have been
most satisfactorily reached lately at the Ber-
lin Royal Experimental Institute. The pow-
der is prepared with extreme care. 80 that the
grains shall all be OF one size. In carrying
this out there are employed conical glass ves-
sells havinga small aperture In the apex OF the
cone. and the polishing material being mixed
with water and occasionally shaken up. passes
ferent sizes and numbers. according to the
time taken to settle the finest kinds being
polishing the specimens. hifh'raH@ Which are aboSt Ut
one-half inch square and a bare, six:
them arc OF m ds y sds % OF
yeniently contact form. and m ordinary glass
lens lens polishing machine arnlied to them. or
specimens are thoroughly cleaned from any
particles OF cement that may be, adhering to
sDecimens.one OF the principal points to
be attended to in microscopical research-is
ssd.r ssst rS ty ypG M ,e tS
different degrees Of coloring In each and this
coloring brings out. of course the various con-
stituents OF the material.
II all the properties claimed for the new ma-
terial manufactured in Germany. and known as
Xylolith. can be substantiated. the Engineering
Magazine thinks the article ought to be vaua-
BILE for use in tagging steam boilers and steam
cylinders. The name. meaning in its deriva-
tion wood and stone. implies for the substance
the nature OF both those materials. and it is
specia! ingredient or ingredients not yet
announced. Its leading properties. which
poses. are stated to be non in am ma bility
non-conductng power. inperviousners. free
hiGn polish-qualitios, which added to tie fact
that 1t Is cheap enough to compete with wood
in architectural uses. are just the requirements
for steam lag.lng.and tnerr appears to exist
no mechanical ditiiculty in thus employing it.
since. according to the descriptions. it can De
advantagoously worked like wood
Another submarine boat has been brought
to public notice. this time the invention Of a
Haverhill, Mass. genius. The boat is of the
cigar shape. twenty-one feet long. and five feet
in diameter at the largest section. and OH the
inside OF this shell hangs cradle. fifteen and
one-half feet long. on points carrying the
burden. machinery. operator and ballast: also
an electric three-horse power engine. from
which the outside shell is made to rerolve rap-
idly and this shell being furnished with fms.
speed. The stern has thrco distinct move:
ments. one that allows the hull to rotate and |
dve aifnr proeer but wcn IS sie9 ony USED
when landing or taking IN air when the hatch-
way is open. The air is furnished from two
water, ana when on the surfacethere is q sue
tion pipe through stationary part OF the stern.
The latest use Of metallic sodium is the prep
aration Of sodium peroxide, by London |
company, In n form suitable for bleaching. |
This compound says the Engineering and Mn |
ING journal. has not hitherto been used COM
and in fact is chiefly known on ac- |
count Of the ease with which it Is formed III |
tho attempt to produce an absolutely pure |
hydrate of soda. In preparing this compound. |
commercially metallic sodium is placed In a |
series Of aluminium dishes which run ON rails |
inside an iron tube. tho interior OF the latter |
being kept at a uniform temperature OF three |
freed iron moisture and carbonic ncid is fed |
into the tube ut the end at which the aiumi- |
mum vessels como out. aud are replaced by
others newly filed with sodium at the other
end-th amount Of air and the speei Of the
Inc OF vessels having to be arranged Accord
Ing rs experience dictates The air perox-
ldizes the sodium in its passage over the ves-
sells. and. when il is ricnest IN oxygen. viz. at
the end where the vessels como out, 1t acts on |
the sodiu which Is the most peroxidized. and |
30 completes the oxidation.
The experiments made by Mr.. yelley OF the
Oxford University Museum. England. on the
action OF nitric acid on various metals. have
shown that the violent action
which nitric acid has upon many metals is due
10 the presence OF q trace OF nitrous acid in the
nitric. Spheres OF copper were kept in nitric
acid OF tho strongest description and freed
from the presence OF nitrous acid. for some
lime. without any reaction occurring but when
once trace OF nitrous acid or of any nitrite
was added the copper was at once dissolved.
The same Kind OF result was observed when
mercury. silver. or bismuth was exchanged
FOr the cONppr-it being also found that from |