Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1876-07-26
MECHANICAL AND SCIENTIFIC.

Several Danish scientists have pro-
ceeded TO Iceland to study volcanic
phenomena.
An alloy of 24.5 of aluminium and
1915 of iron is silver white, and does
not rust in the air.
The manufacture of lamps and
tumblers toughened by the newly dis
covered process has been commenced
on small scale at Philadelphia.
The Austrian expedition to the
north pole reports as to the relation
between Aurora bolealis and its mag
netic perturbations, that in the re-
gions where the aurora exhibited its
maximum power the deviation of the
magnetic needle was toward the east.
The declination diminished, but the
inclination always increased.
That there are certain irregulari-
ties in the level Of the sea, or local de-
viationS from true spheroid, such au
thorities as Stokes, Airy, Sabine, Fish
er and Testing have long believed.
DR.. Hahn, of Vienna, draws attention
to these irregularities, which, he
thinks, are very considerable, exceed
ing, perhaps, 5000 feet. DR.. Hahn
proposes, by means of the pendulum,
to thoroughly study this interesting
problem, this being the best instru-
ment for measuring attitudes, if 10y al
titudes we understand the elevation
above the regular spheroid, and not
merely above the level Of the sea.
These deviations of the sea level are
caused by the attraction Of land masses
as well as by the varying depths Of the
ocean.
in the Patent Rotary Web Per-
fecting Press, with folding machine
attached, made for the Philadelphia
Times, the printing and folding are one
continuous operations. The paper
| from the roll enters between a type
and impression cylinder and is printed
on one side, thence passes between an
other type-cylinder and fellow i'm
preston or set-off cylinder of four
times its size, and is printed on its
second side. AS this set-otf cylinder
has four blanket surfaces, the machine
viii print four times as many impress
sions as Il single blanket cylinder
would before the set-off begins to
show. The printed web now passes
between pair of cylinders that cut it
| croSsWiSe into sheets, and these are
taken by folding cylinder. which, by
a newly-patented mechanism, gives
| them their firSt-fold AS this machine
prints double sheet, they are now
cut III two longitudinally by circular
cutter, and switched off alternately
into two different paths. These single
| sheets are now crosS-folded, and as
they issue from the folding rollers they
are caught by Il Ely" and deposited
in neat piles on balanced table that
sinks as the papers accumulate and
rises as they are removed.
Though modern church architec,
| ture is constructed on acoustic princi-
pies, it frequently happens that the
voice of the speaker is lost. Especially
is this the case when the building has
numerous subdivisions, such as of
vaults, aisles and chapelS. In many of
such larger edifices, the use of sound
| ing boards, back and above the pulpit
| become necessary. The american
architect and Building Nelrs gives a
| brief notice of such constructions. 1t
explains that in addition to peculiari-
ties of form, which must be adopted to
| the coniguration of the building, such
screens should have a certain soldity
of construction. 1t is not required
! that sounding boards should have a
Migratory influence, which would be
the case it they were made of thin
wood, but that, being bulls solid and
of heavy oak, they should have the
power of rejecting sound. Mention is
made of such a defective sound board,
due TO a firm of piano makers, the
wood employed being such as was used
in the construction of their instru-
ments. This instead of rejecting the
sound rs it WAS intented to do, and us
heavier wood, would have done, alb
sorbed the sound into his own mass,
and yibrated with the air.