The Lorimer system was developed in the USA and Canada by three brothers, George, Holt and Egbert Lorimer. They patented the system in 1900 and their system was manufactured by the Canadian Machine Telephone Company of Toronto and the American machine Telephone Co. Ltd. They were installed in Europe and North America.
The telephones used a "Signal Generator" to transmit the digits required to the Exchange. On the front of the telephone were four levers and a window associated with each lever would show the number required. The user would select the number required (0 to 9999) using the levers and then turn the crank on the side of the phone one revolution. The crank tensioned a spring which operated the "Signal Generator" and signalled to the exchange that the user was ready to make a call. The user then lifted the receiver and the "Signal Generator" was connected to the exchange. The exchange was then in control of the "Signal Generator" and signalled when it was ready to accept the call. The levers then remain untouched and could be made to call the same number again just by turning the crank and lifting the receiver. This was probably the first "Last Number Redial" facility on a telephone!
The levers could also be locked (inside the telephone) in any combination of numbers so only one number could be dialed. This would probably be used in public areas were only one number dialled was required e.g. a Taxi company number.
The the only Lorimer exchange was installed in 1914 at Hereford. This was experimental exchanges but was in use for a number of years.
The telephones below were the models used by the GPO. Earlier models were in the typical American fiddleback style with the four levers fitted at the top and a metal plate around the levers with the inscriptions "Automatic Telephone" and "The Automatic Machine Telephone Co. Ltd".
Last revised: October 06, 2020