G.P.O. GMT 34 and Clock 36

Used by the British G.P.O for many years, this is a Master clock No. 36, being run from a clock unit GMT 34. These would run the slave clocks in a building plus the timing for Strowger telephone exchanges.
More information on all G.P.O. clocks can be found at:http://gpoclocksystems.byethost22.com