The sun. [volume] (New York [N.Y.]) 1833-1916, 1898-03-06
VOTES ON soIENor AVID INDUSTRY.

he the most subject to Injury. Resort Is had by
those working the searchlishts TO tho wearing Of
dark blue glasses. These. however, while tcnding to
mitigate the intensity OF tho light, fail to absorb the
source Of the trouble, namely, the ultraviolet rays.
The latter. nevertheless, can be intercepted by goggles
or screens Of uranium. or yellow glass. and these, II 10
expected, will in course of time be extensively intro
duced. Operators with the electric drill-burning
out holes In a hardened steel p~late-havo sometimes
had to be treated for intense pain and partial blind.
ness. This kind OF drili, as IS known, acts by fusing
a hole through the steel. uni the intensity OF the
light ia greatly increased by the rays thrown OF by
the molten metal. The use OF dark glasses by those
engaged In this kind OF work has proved a great
boon In obviHting its otherwise disastrous effects.
A singular feature OF tho injury done to tho eycsiEhtiS
n remarkable similarity to snow or de'ert blindness,
being. ns In these. probably due to the ultraviolet
rays of the spectrum.
Some of the western railroads are making extou.
awe use. as ballast for their tracks. of gumbo. n sort
OF clay found In largc quantities In that part OF the
country, aud declare | TO be the best possible material
for that purpose after having been burned. With
this in view. n track Is laid in a field. sometimes n
mile long, and. moving along this track, immense
steam shovels take up the clay from the trenches on
either side; a bed Of old ties and other
stun laid along the intended trenches IL covered with
about one foot of the gumbo; then follows q
covering OF fine coal, which Is spread over
the gumbo several inches thick. the steam
shovels, again travelling the entire length OF
the kiln. throwing up on top of the coal another foot
OF the raw gumbo, This process continues over and
over again. the trenches getting deeper and deeper
and the kiln higher. until n depth OF ton or twelve
feet ia attained. At this stage the shavings and kin.
dlings which have been placed between the old ties are
set on FIRE. and the burning continues until the material
takes on a bright red color. when It Is in the proper
condition to be used for ballasting. Gumbo also pre-.
vents the growth of weeds.
Utilization, in its chemical forms. could scarcely be
expected to exhibit itself in m achievement moro
curious or more serviceable to the public than In tho
treatment OF condemned meats by tho authorities OF
London. over nine hundred tons OF this viilainous
material having come under tho offcial ban during
the last year. As soon a. the substance ia seized. II IS
hacked and slnshed about with knives, to render its
appearance unlike any meat for the market. and is
then thrown into q chemical bath. to remain there
cooking for SOM time. The meat is treated with
chloridcs OF calcium and soda, and afterward with
sulphate of iron. which renders It black, %unsightly. and
nauseous. BY this time II has become a pulpy mass
OF decomposed tissue. almost beyond recognition.
and is now treated with picric acid, which turns II n
bright yellow. Atthis point the Official authorities have
done with It and It is given over to the contractors.
who remove 1t to their weliequipped works. where.
in stcam.jaoketed pans. the mass is thoroughly boiled
down for the fat. which is used in the manufacture
OF candles and soaps. The bones are collected and
duly sorted. the smaller and inferior ones being re.
duced to powder. which is used for phosphates. The
residual liquor Is used for land dressing.
In recording the fact Of the recent greatly reduced
price Of aluminium. the Manufacturers Gazette says
that such reduction Is likely to advances tho favor
which that material has received in the arts and in.
dustrles, and to lead to its entry into new fields as a
competitor of other metals This notable reductton
such. IL is alleged, as to make sheet aluminium ONE
10 per cent. lower in cost than sheet brass-is q most
important item; thus. sheet brass being $40 times
heavier than q similar sheet OF aluminium, the alumni.
mum equivalent for a foot square of a sheet of brass
of any given thickness is found by multiplying the
brass price per pound by this factor. According to
manufacturers estimates, at 32.49 cents per pound
aluminium ia more than 10 per cent. cheaper than
the lowest comparative rate per pound now ruling
for brass. As now appears, therefore. iron. zinc. and
lead are the only metals used In sheet form that are
cheaper than aluminium.
The plans which have been matured by Prof. wads.
worth OF the University OF Chicago for q more eff.
fective system OF photographic nebule. are of q
character giving much promise ot future results.
Most astronomers are Of the opinion that the reason
why the photographs of recent date do not show the
fainter details Is that. under favorable circumstances.
there ia enough light dinused In the sky to produce,
after a time. the well.known foggy effect which IS
found on any overexposed plate. But It is declared
by Prof. wadsworth that the length OF the exposure
without Jogging depends on the aperture of the instru.
ment. He considers II a more important fact, however,
that the ratio between the brightness of the luminous
images can be controlled. Thus. II q sensitive plate
be placed nvo inches from n one.iuch lens In one
camera and ten inches from q two-inch lens in
another. the same amount OF sky would be covered
In both cases; but the former instrument would get
details four times as faint as the other in the same
time or would do the same work as the other instru.
ment In one-quarter OF the time. 1t 10 this theory
that has led Prof. Wadsworth to mount two object
glasses from a Zeiss microscope, having a%pertures OF
only o.2s and o,42 respectively. ana with these TO
photograph ebule never before known.
Fibre from the pineapple leaf will eventually take
0 prominent place among the commitments OF textile
fabric. according to statements made In the report OF
the United States Department OF Agriculture. The
report shows thai both the wild and the cultivated
plants Of this description yield fibre which. when
spun. surpass in point of strength. nneness. and lustre
those obtained from fax. Summarizing its value,
mention is made OF its usefulness as a substitute for
silk and as q material for mixing with wool or cot
ton-useful. too, for %cordage. sewing silk or twist,
laces. &c. In China Il is used IN fabrics for clothing
for agrIculturlsts: It Is In request in India as material
for stringing necklaces. and is the substance of tho
well known pima cloth OF the Philippine Islands. II
is remarkably durable, unaffected by immersion in
water. is white. soft. silky. flexible. and long In
staple. Samples cleaned. without washing. when
twisted to the size OF binding Irvine. have shown q
breakage strain of 100 pounds.
A simple test for noxious gases in the air OF mines
Is explained by q writer in the Coifery Guardian
England. For detecting carbonic oxide. methane.
&C., q dilute solution Of potassium permanganate.
containing a little nitric acid. is found highly erncient.
the effect of such gases being to decolorize the per-
manganate solution. The reaction goes on more
rapidly when the solution also contains silver nitrate.
one part OF carbonic oxide to from 600 TO 5000 parts
OF air decolorIzing the liquid In from one to twenty
four hours The rengcnt consists OF two or three
grammes of silver nitrate crystals dissolved in one
liter OF water; then for the potassium permanganate
solution. one liter Of distilled water boiled with a