First transatlantic telephone call

Although submarine transatlantic cables have been used to conduct telegraph communications between Europe and America since 1858, the very first transatlantic telephone cable capable of relaying speech was not started until 1955 (the same year as Guinness World Records published its first edition). Transatlantic Number One (TAT-1) was laid between Gallanach Bay near Oban in Scotland and Clarenville in Newfoundland, between 1955 and 1956. Formally opened for business on 25 September 1956, TAT-1 was based upon 36 telephone channels that carried 588 London, UK–USA calls and 119 London, UK–Canada calls in its first 24 hours of public service. The capacity of the cable was soon increased to 48 channels to cope with demand. The project was a joint agreement between the UK's General Post Office, the American Telephone and Telegraph company, and the Canadian Overseas Telecommunications Corporation. The total bill of £120 million ($191 million) was split 40% Britain, 50% USA, and 10% Canada.