The Opelousas courier., 1888-02-18
SCIENTIFIC SCRAPS


monds are brought nearly to that deli
cacy of balance which would enable
dealers to detect flaws in the stone by
minute variations in weight. They
weigh accurately the G40th part of a
carat.
Workmen who were digging a ditch
in Montgomery County, Ind, struck a
stratum of earth resembling white clay,
which turned LACK on being exposed to
the air. Pieces of it thrown into the fire
were found to burn t~iercely. The sub
stance is supposed to be coal of the first
formation.
Therost of mining and milling gold
ore at the Spanish Mine in Nevada
County, Cal, has been SO reduced that
ore worth only ST.. Is a ton can be mined
and worked at a profit Of about ffty-six
cents a ton. The cost Of mining nearly
5000 tons was only 81 1-2 cents a ton,
and Of milling it twcnty-thrce cents q
ton. G
Among the "fowls of the air. are
three, the eagle, swan aud raven, which
live to the ago of 100 years or more.
The paroquet and heron attain the
goodly age of sixty years. The spar
row-hawk, duck and pelican may live to
be forty, while the peacock and hnnet
reach the quarter century, and the
canary tw%enty>four year.
The g1Gent tearing down of q New
Hampshire mandatory by means of dy-
Mantle, demonstrates a new use for the
explosive. The conclusion completely
separated the bricks and did not seem
to in jure them u the least; the charges
were put in holes dug in the foundation
under the brick wall, and the number of
cartridges were graded according to
the number of bricks in the wall to be
demolished.
1t is stated that soft soap with half its
weight in pearlash, one ounce of mix
ture in about one gallon of boiling
water, is found of great practical value
in engineers shops, in the drip pans
used for turning long articles bright in
wrought iron and steel. The effect of
this mode of treatment is that the work,
although constantly moist, docs not
rust, and bright nuts are immersed in it
for days till waited, retaining their
polish.
The interesting fact is stated that so
i~ndestructible by wear or decay is the
African lockwood that vessels built of it
have lasted one hundred years, to be
then only broken up because of their
poor sailing qualities from faulty models.
The wood, in fact, is one Of the most re.
markable known, on account of its very
great weight, hardness, and durability,
its weight varying from forty-two to
fifty-two pounds per cubic foot; it works
easily, but on account of the large
quantity of slick contained in it the
tools employed are quickly worn away.
1t also contains an oil which pre-
vents spikes and other iron work with
which it comes in contact from rusting.
A celebrated physician has remarked
that every house ought to be pulled
down at the end of the sixtieth year, as
1t has by that time absorbed all the dis
eases Of those who have lived in it, be-
lieving that wood and plaster absorb
gases, foul air and feverish exhalations
as readily as milk or water docs. But
as it is not practicable to tear down
houses every half century or so, it is to
be considered if all the wood used in the
interior construction and all the plain
surfaces of plaster should not be so
thoroughly oiled or vanished that the
power of absorption should be almost
entirely destroyed, and the character
thus so changed that destruction would
be no longer desirable.