The Cambria freeman. [volume] (Ebensburg, Pa.) 1867-1938, 1877-01-05
EE5r1RRABLE CLOCKS.

We gave. on page 81 of this vol
me, a description of clock, which
has the odd and feature that it oscil-
lates while the pendulum is stationary.
The novelty of this clock (the inven.
ton of ". Guilmet) is in the form
the principle is old, and clocks may
be seen, suspended in shop windows,
which osciilate ike pendulums while
the escgpa wheel works on an anchor
on the top OF a pendulu n rod, which,
however, In place Of being movable,
is fixed in the table under the clock,
making It stationary; while the escape
wheel, by the reaction Of the pressure
Of its teeth upon the anchor, moves
to the right and left. and communicates
this movement to the whole clock.
Usually the suspension rods OF these
clocks are of such length as to make
the whole clock G. second pendulum
and these rods are composed OF bars
Of steel and brass, to compensate pro-
perly for changes Of their length by
Temperature Ir. this case, these
clocks are, if well made, excellent time
pieces and they are often used by
watchmakers rs regulators.
Another remarkable kind OF clock
which recently has been imported, and
put on exposition in New York city,
consists of glass disk with the figures
OF the hours on it and hour and minute
hands loosely slipped on n pivot in
the center. The hands can he taken
off. and no works Whatever are visible
nor can any connection Of the hands
with ANYTHING be seen, nOtwithstand-
inc that the hands point always to the
right hour and minute; and even
when turned round or even whrled by
hand they will, after some revolutions
and oscillations, come back to the
right place They are well called
mysterious clocks, and spectators are
assured that they are not moved cy
electricity This IS true and the
Khole secret is in the cOuntcrpOise OF
the hands, each of which has heavy
arrow point at the long end, and at
the short end hollow round box. In
this box are the works Of a watch,
which are so placed as to leave an an
nular space between them and the
circumference Of the box; and in this
space in counterpoise which is con-
nected with the works so as to revolve
once in u hours for the hour hand,
and once in an hour for the minute
hand the revolution of the counter
poise inside the box shifts the center
of gravity OF the hand so as 20 give
the hand, successfully, the necessary
direction. Thus when the couuterpois
is the furthest from tile axis, it brings
the center OF gravity opposite the ar
row point, and the hand will point up
ward to u; when on the contrary,
the counterpoise is between the axis
and the arrow point, the center of
gravity will be there, and the arrow
viii point downward, to s. In the in
termo6iate steward position of this
revolving counterpoise. the center of
gravity Of the whole will he displaced
sideways. and the hand point Mt 8. 9,
10, or ,. 3, 4. according to the shifting.
This clock was patented in this coun-
try on September l, 1874, by Henry
Robert, q clockmaker Of Paris. France
Lately Mr. Robert has considerably
improved on the plan, especially by
using very light and very heavy
metals in combination, so as to have
a sufficient contrast in weight for OBJ
tanning :he right effect. The hidden
counterpoise. moving in the hollow
box, is of platinum, so as to take up
a little room as possible, and the hand
with its arrow point is of aluminium,
the lightest known metal Scientific
american.