The citizen. (Frederick City, Md.) 1895-1923, 1896-05-08
written for the CrrIzKNl

Not the least marvel of science is the
degree of refinement to which its
measurements are now carried. Lens
curvatures of 1-15O, 900 of an icnch. ac-
cording to Engineering Mechanics, can
be measured. In spectroscopic analy-
sis of mere traces of different elements,
fractional wave lengths are read to
1-25O, 600 millionth of an inch. Prof.
Dewar, in his researches in liquid air,
attained a vacuum of l., 500 millionth
of an atmosphere by filling vessel
with mercurial vapor and exposing it
to very low temperature; and Prof.
Boys, with a simple arrangement of
quartz fibre. torsion balance and mir
ror, claims to have been able to just
detect an attractive force of 1-2, 600 of
a grain. In angles the Darwin PEN
dulum will indicate a movement Of
1900 of a second-about the angular
measurement of penny piece at a dis
taDce of l 900 miles.
The luminosity of nudge (ChirOn-
onlus plunaOslEsI, which has sometimes
been observed in Russia, Persia and
PoIneranio in such numbers as TO make
whole trees glow, is now attributed to
bacteria. Such organisms have not
been actually discovered, but the flies
appear sluggish and sickly, as does q
a luminous beach shrimp, which has
been found TO swarm with bacteria
capable of impaTting phosphorescence
TO healthy, non-luminous shrlmps.
An interesting suggestion concerning
FL, - IF hn
glow-worm is that the creature con-
tains fluorescent material so sensitive
as to respond TO atteuuated y rays
which may be everywhere present.
Earthquake oscillations are now
measured by delicate instruments thou
sands of miles away, aud there is no
doubt that in the future they may be
traced around the earth. Prof. Milne
believes the earth pulsations TO be
long, low waves. DR.. Charles Davi-
son shows this to have been true in
one case at least, the Greek earthquake
of April %, 1894, having been register
ed in Birmingham, Eng, where the
largest pulsation seems to have had q
length of about Is miles and a height
of half an inch.
The germs of an important scientific
discovery may he found. Mr.. Alex.
f. Outerbridge, Jr., has pointed out,
in the proof that cast iron does not be-
come brittle under repeated shocks, as
generally supposed, but that the metal
really undergOes a kind of cold anneal-
ing under shocks not too severe, and
has its strength increased. This was
-
test-bars that had been knocked about
for a. number of hours in a tumbling
barrel showed gain in strength of
from 10 to Is per cent. The same re-
suit was obtained by giving one end of
bar 8, 900 taps with q hand hammer.
1t is claimed that every new casting is
under a condition of strain due to the
varying rate of cooling of different
parts, and that repeated tapping may
relieve these strains by permitting the
metallic particles to rearrange them
selves and assume new condition of
molecular equilibrium. A thousand
tests maintain the correctness of this
view. The experiments lead to the
conclusions that new castings should
not be suddenly subjected to tests ap-
preaching the severity of intended SER
vice; that is perfectly practicable TO an
neal castings by shocks when cold, as
is done in service, the old castings be-
coming more reliable; and that il is
most important to apply this method
to strong iron castings and castings of
irregular section, as in these the initial
strains are greatest. 1t is probable, but
not yet proven. that steel and all met
ais may be subject to the same law, aud
that new guns may be relieved of
strains and strengthened by prelinli-
nary small charges of explosives
Of the many hundred fibre plants
known in the world, only Is, according
to Mr.. Z. III. Dodge, are recognized in
the United States as of commercial i'm
portance, aud only four of these-cot-
ton, hemp, palmetto and Spanish moss
are produced on a considerable scale
in this country. The other CONNER
cial fibres that might be advantage
Ously grown in some sections are fax,
jute, sisal. hemp, New Zealand fax, CO.
coanul, aud possibly sum hemp.
1t has been practicable to propagate
sugsr-cane only by cuttings or their
equivalents, aud the lack of seedlings
has been difficulty in the way of i'm
provement. From the 200 or 800 vari-
cites experimentally grown in Java,
Mr.. J. III. Walker has been able to Sc
lect a few plants that by crossing have
given very good seeds. These have
given vigorous seedlings, which yield
more sugar than the parent plants, and
promise varieties more profitable than
any hitherto known.
Seeking to extend the usefulness of
aluminium, NJ. Charles MargOt, of Gen
eva, has prepared some very interest
ing mixtures with other metals. With
Is per cent. of aluminium and - of pla-
tinuTn, he obtained an alloy of golden
yellow color. which is stable but brittle.
Varying the proportions of the constit-
uents gave other tints, but such mix
lures were unstable and broke up spon-
taneously. With 20 to % per cent. OF
aluminium to IS or so of cobalt, the color
ranged from straw to brown, and the
metal was so hard as to scratch glass,
but very brittle and easily powdered.
An alloy of aluminium and palladium.
in the proportion of . and - respec-
lively, was cOpper-red in color, stable,
hard and brittle. An alloy or Is pei
cent of aluminium aud 50 of nickel was
straw-cOlOred, much less brittle than
the Others, had the hardness of tenn.
pered steel. took fine polish, and re.
sembled bell-metal in fracture