|P.O. ENGINEERING DEPT.
Issue 1, 27/10/38
WATCHMAN’S PORTABLE TELL-TALE CLOCK
“Clock No. 15”
”Clock No. 15“ is a portable tell-tale clock which has been provided in large P.O. buildings for checking the times at which the night patrol reaches certain points in the course of his rounds. At these positions a numbered registering key is
fastened to the wall, etc., by a chain. This key, when inserted in the portable recording clock carried by the patrol, causes the number of the
point and the time to be recorded on a paper roll or disk inside the clock. There are three types of tell-tale clock in use, one of which, with the key, is illustrated.
The clock is now obsolescent and will not be installed in future buildings. It has been superseded by an electrical system (see