The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-12-14
rHILADELPHrA's NEW CLOCK.
The Huge Affair of the City Hall to
Be Started on Dec. 81.

From the Philadelphia Times.
The great clock in the tower of City Hall
is running, although this fact is not yet
apparent to an outside observer. The
clock will be kept in operation for a month
in order to test its accuracy and its hands
will begin to move at O'Clock on New
Years eve.
To most people the marvellous intricacy
and the magnitude of the big timepiece
would prove a surprise. 1t seems to be
popular opinion that the clock is run by
works located behind the dial and similar
to those concealed in the interior of an or
binary mantel-shelf chronometer. The
mechanism that controls the mighty hands
of the city clock is vastly different from
common clock works.
The hands of the clock are to be moved
by machinery, stationed more than 100 feet
below them. The main mechanism, or
master Clock as it is called, is located
in the seventh floor of the tower. In one
corner of the tower stands huge glass
cabinet which, with the addition of flow
ers and plants, would make a good con-
servatory.. This cabinet is ten feet high,
fifteen feet in length and. although seem
ing TO rest on the floor, is in reality sus-
pended by iron beams protruding from the
tower walls The cabinet is almost as care
fully made as Inc clock itself. The frame
work is composed of iron and soft pine,
the whole being overlaid with copper. A
mahogany door leads into the cabinet, and
when this is closed the cabinet is alb
solutely air tight and dust proof.
Standing inside the cabinet on perfect
Nv level marble floor are Two clocks, four
feet in hight and inclosed in cases of
glass and ebony One of these clocks is
the vital part of the elaborate system, the
other clock serving as an auxiliary. The
interior of the cabinet is kept at one tenn
peratlre by means of a thermostat that
automatically turns off or on the current
generating heat in an electric coil.
The master clock was made in Glasheut-
ter Saxony, and required two years in
IFS manufacture. 1t is SO arranged that
knob attached to the long pendulum opens
valve at every half minute. The open
ing of the valve permits a current of COM
pressed air 10 flow through a small brass
nine 10 the central movement, which is 100
feet above in the chamber of the tower
behind the clock faces. Whenever the
valve is opened the compressed air pushes
forward or backward a delicate diaph-
rapm. which by its movement causes a
toothed wheel to revolve through def
mite arc. To this toothed wheel is at
tached by a universal joint a long brass
rod that runs to the axis of the hands
in the big clock and turns them. 1t will
he seen. therefore, that the hands of the
clock move at intervals of thirty seconds
the minute hand describing a complete
circle by a series of 120 short advances
For each of the four dials there is a cen
tral movement. ali four movements being
operated stimuli aneousiy by the compress
ed air liberated by the master clock"
In addition TO this careful and complete
arrangement are the three electric pumps
that work automatically and keep the air
pressure at ten pounds. To protect
against accidents two other pumps have
been placed in an entirely different part
of the city hail, and in case the air pres
sure should fall through accident below
seven pounds the two distant pumps would
take up the work.
The dials are 10 be Illuminated a night
by $50 tncandescent lights, and in this con-
nection there is another interesting auto
matte arrangement that turns on the
lights whenever darkness comes. Inside
the cabinet behind the master clock -
is a telephone connected direct with Wash
ington, and through il the ticking OF the
astronomical clock IN the government OBJ
servatory can be heard BY this means
any error 10 the reading OF the city hall
clock can be detected and corrected.
Each hour hand Is 10 feet 3 inches and
each minute hand Is Is feet inches in
length. Each hand weighs 400 pounds. and
Is made Of brass. The entire clock cost
the city $4,000.