Unknown maker with dual high quality Seth Thomas movements
A three quarter view of the timer in its heavy cast bronze case.
Front elevation showinf central dial and dual Seth Thomas movements behind heavy
bevel glass door.
Views from above with the dust covers removed.
The first photo shows the left movement with the dust cover removed and the
right with the cover in place. The second photo shows the double plate
construction of the pair of movements. The lower subsidiary plate supports the
winding wheels for the dual springs found in each movement.
The first photo shows a close up of the main setting dial. The interior dial is
composed of two sliding sectors allowing the operator to set the number of hours
that the alarm is to be on guard. The outer dial is set to the current time and
is delineated into two twelve hour sectors. The second photo shows two contact
wheels. The one to the left is the setting or warning signal to alert the
operator that the alarm is about to go on guard. The other wheel is engaged by
the rim of the setting dial and keeps the alarm on guard according to the
setting that the operator has chosen. The design is reminiscent of the
Holmes Model 2 time lock
dial arrangement.
Here are two close up views of the Seth Thomas movements. Notice the fine rate
adjustment for the platform escapement; the use of a helical gear for this
purpose.
Bank alarm timer, unknown maker, c.1900. This bank alarm timer uses two independent Seth Thomas movements
within one unit. Many alarm timers had two separate timers each contained
within a wood case and often used a lesser quality and much larger Seth
Thomas #10 movement. A few were single units utilizing standard time lock
movements within a similar style case or a small metal case. The Seth Thomas
movements used here appear to have been originally made for the marine
market. The design of the case and glass indicates that this was intended
for a proof of concept and would have entailed an unnecessary expense for a
production model.
Many alarm timers were expected to be set at the time the alarm was
to go on guard, this one allowed the operator to set it ahead of time and a
separate warning would sound when time was approaching for the timer to go
on guard to alert the personnel to close up the bank.
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