The Bolivar bulletin. [volume] (Bolivar, Hardeman County, Tenn.) 1865-1888, 1879-11-27
USEFUL AND SCIENTIFIC.

CURIOUS SCIENTIFIC INVENTION
An ingenious invention has been ar
ranged by which the hour of the day
may be sounded on bell at any prede-
termined hour. It comprises lens by
means Of which the solar rays are con-
centrated and directed to q metallic slip,
which is susceptible of very rapid dila-
tatiOn. The result of the dilatatiOn is
electric contact, giving passage to a
battery current which rings a bell.
Even when the sun is obscured by clouds
the calorific power is sufficient to work
the machine. 1t would be interesting
to test this instrument by the action of
the moon through a lens of high mag
nifying power on very sensitive strip.
WELDING CAsT-IRON.-The Chinese
process of welding cracked cast-iron
wares with molten ironis thus described
in the Iron Age: % In the case, for ex-
ample, of cast-iron pan requiring such
treatment, the operator commences by
slightly breaking the edges of the frac-
ture with a hammer, in order to enlarge
the assures, after which the fractured
pieces are placed and held in proper
position by means of wooden braces.
The pan being ready, clay crucible,
charged with pieces Of iron, is laid on
ignited charcoal in a small portable fur
mace of sheet-iron, provided with hOr-
izontal bellows. AS soon as the iron in
the crucible is melted, it is poured on a
layer of partly-charred husks of rough
rice, spread on pad of folded cloth to
prevent the sudden cooling of the metal.
While yet liquid, the metal is forced
with jerk into the assures, and pa
per rubber is pressed over the obtruding
metal inside the vessel, making a strong
and thorough job"
STONE-CUTTING MACHINERY-Bya
recent invention great blocks of granite
or other stone may be smOothed with
about the same rapidity that iron is
planed by the well known machinery
used for that purpose. The cutting
tools, two in number, are arranged in a
strong head-piece attached to moving
| platen, similar to the iron planning ma
| chine; the platen, with the head-piece,
being made to move forward and back
ward over the stone, and the tools, hav-
| ing perpendicular, reciprocal, rotating
motion, cut the surface at the rate of
not less than six thousand blows per
minute. The rapiditv of this motion is
! said to be of great importance in the use
/ of the tools, the wear being much less
than in hand-wOrk. These cutting tools
/
and can be used constantly for three
quarters of an hour without changing,
so that one set of tools will thus make
more than quarter of a million strokes
without resharpening. By adapting a
movable arm the tools are made to
cut irregular forms, such as cornices,
holdings and letters, with as much pre-
cision as they cut plain surfaces. This
remarkable machine is operated by
steam power equivalent to that of a sin
gle horse, but is said to do the work OF
dozen or more men within a given
time.
THE " WONDERFUL g" MINERAL
Prof. Nordenskjold has communicated
to the Paris Academy of Sciences an in
teresting account of the peculiar mineral
recently found in Sweden, and which
has been named Thaumasite, or " the
! Wonderful from its curious qualities
or characteristics. The author of this
paper states that the mineral in ques-
ton has been carefully studied by M
LindstrOm, with some valuable results
1t appears that the article has been me-
with in specimens brought from the Gus
tav and Carlsberg mines, or the Bjelkt
mine at Areskustan, some 20 years ago;
also in specimens of an old Swedish col
lection from the same mines as many as
100 years ago, by M. Policemen, a min.
ing engineer; and, lastly, the specimens
brought from the same mines, at the in.
stance of Prof. Nordenskjold, after close
analysis had demonstrated the strange
composition of the substance, which con
tains at once silicic acid, carbonic aciC
and sulphuric acid. 1t is further shown
by microscOpical examination, that thi:
mineral is an entirely new species, anC
not mixture, and, in fact, the compost
ton of the mineral is in some respect:
so curious that biologists are of the OPin
ion that it may furnish some impOrtan
knowledge concerning the transforma
ton which the materials of rocks have
undergone, and to which they are sub
ject in the course of ages.