The Burgot Automatic Alarm was originally invented by a Mr. Mountstephen in 1938. When activated, it automatically dialled the police emergency service and played a recorded message that identified the location of the premises. As external sounders were not used, this machine was an effective "silent alarm" which resulted in very successful arrest rates for the Police. It was said that many a Burglar caught in the act, could not understand how the Police had been tipped off and assumed an accomplice was responsible for informing the authorities.
In 1948 Burgot was acquired by Radio Rentals and traded as Burgot Rentals Ltd. Radio Rentals was an organization who specialised in renting radios and televisions, such items were popular but expensive, and renting was widespread in the 1950's. In 1958 Radio Rentals sold the burglar alarm business and it became Burgot Automatic Alarms Ltd. During this period Burgot began publishing figures of arrests resulting from their silent alarms. These were very impressive and resulted in the growth of the company not only in London, but in other major cities in the UK where crime was a problem, such as Liverpool, Glasgow, Manchester and Birmingham.