The Sterling Telephone and Electric Company began around the early 1900s, building parts for the new electricity industry. Telephones were introduced as a sideline, one which became quite profitable for them. Initially they built phone parts, but soon added their own intercom systems to the range. They also started to build telephone exchanges and full phones for the British Post Office. Sterling's giant Dagenham plant was a showpiece of British industry.
This little desk phone is an example of their intercom range. It is missing the bottom woodwork that contained the wiring. It probably dates from before World War 1.
These intercoms could be used as point-to-point intercoms, or could be connected to a larger switchboard. Many were sold around the world, and they are fairly easy for a collector to find and not too expensive to buy.
This next model is a a widely used wall intercom, with what appears to be a Hunnings transmitter. This basic wooden box wall style was also made by many other manufacturers.
Intercoms are often looked down on by some collectors. This is a pity, because they are often the only remaining artifacts of some of the earliest companies. Sterling closed in 1925 when the company was bought out by Marconi. Marconi used the Sterling manufacturing facilities to build radios (sorry, wirelesses) for the new public broadcasting industry.