BT makes digitised version of its archive available online

6 min read

The contrast between 10 year old communications technology and what's available today is stark. If you go back to 1846, that technology would seem positively neanderthal.

Yet 1846 is an auspicious date for the UK; it's when the Electric Telegraph Company was founded – the first business to introduce networked electrical communications and the world's first commercial telecommunications undertaking. BT has a direct line of descent from that organisation and can reasonably claim the title of the world's oldest communications company. As a result, it possesses one of the most comprehensive and valuable technology archives of any company. This underpins a £745,000 project, managed by Coventry University in partnership with BT and The National Archives, to create a digitised online archive of almost 500,000 photographs, documents and pieces of correspondence accumulated and preserved by BT during more than 150 years. As part of its archival strategy, BT has founded Connected Earth (, which oversees historic artefacts in museums around the UK and maintains online galleries offering catalogues of images, artefacts and memories. The archive describes events in the history of global telecommunications; some are of major significance, others just plain quirky. Here's a few examples. First days of telephony The first telephone conversation was 'Mr Watson, come here, I want you', spoken by Alexander Graham Bell to his assistant Thomas Watson on 10 March 1876. Less than two years later, Bell was demonstrating the telephone to Queen Victoria at Osborne House on the Isle of Wight by making calls to London, Cowes and Southampton – the first long distance calls in the UK. In the same year, The Telephone Company (Bell's Patents) was formed to market Bell's telephones in the UK. The company was registered with a capital of £100,000 and premises at 36 Coleman Street in London. One of the first telephone lines to be erected in the vicinity of London was from Hay's Wharf, south of the Thames, to Hay's Wharf Office on the north bank. What is regarded as the first commercial telephone exchange was opened in Connecticut in 1878 while, in Europe, the first two dedicated exchanges began operating in London and Manchester in 1879. The London exchange, sited on Coleman Street, had a capacity of 150 lines and opened with 7 or 8 subscribers. It is a long journey from then to today's all electronic digital exchanges. But the technology that was to dominate telephone exchanges for much of the 20th Century had been patented before the 19th Century was finished – by US undertaker Almon Strowger in 1891. Although the Strowger system underwent many developments, its fundamental character – electromechanical switching to route telephone calls – remained unchanged for decades, until all electronic, digital exchanges took over in the UK from the late 1970s in the form of BT's System X and Y. The UK's first electronic exchange was not digital, but analogue. A BT (or Post Office, as it was then) prototype was tested at Highgate Wood exchange in the 1960s, but did not work well. And the first digital exchange was not System X, but the Empress, which operated in West Kensington in 1968. This was the first example of switching pulse code modulation signals carrying live traffic. Today, state of the art electronic exchange systems are so powerful and compact that a small box can do what once required an entire building full of equipment. One consequence is that many of BT's buildings that housed old exchanges now have huge amounts of empty space. Mobile – from the past The world's first commercial cellular telephone network was launched in Japan by NTT in 1979, initially in Tokyo, but the very first call had been made back in 1973 by Motorola. NTT's network was followed in 1981 by the Nordic Mobile Telephone system in Denmark, Finland, Norway and Sweden and then by several countries in the 1980s, including the UK, Mexico and Canada. The rest, as they say, is history. What is not so well known is that mobile telephony goes back way before 1979 – astonishingly, to 1922! The first demonstration – called Eve's Wireless – was filmed by British Pathé News. It shows two women carrying a box with lots of cords, which they attached to a post and made a call using an umbrella as an antenna. The technology is believed to be a small Cat's Whisker HF radio and the women are even shown calling an exchange which 'downloads' music to them via a gramophone! While this was hardly of practical use, more serious mobile telephony predates conventional cellular systems by more than 20 years. Several radio based public mobile phone systems were introduced after World War II, the first being in St Louis in the US in 1946. The UK saw its 'System 1' manual radiotelephone service for use in vehicles launched as the Post Office South Lancashire Radiophone Service in 1959. Calls were made to an operator, who routed the call to the recipient's land line. The handset, identical to an ordinary telephone, was connected to a large, valve based system housed in the boot and powered by the car's battery, with a conventional radio antenna on the roof. There were about six channels available, some 100 subscribers and a range of around 20 miles. Later on, while mobile telephony was still for the tiny minority, the service had up to 6000 users in London. An improved service, System 3, was extended to cover most of the UK and it survived for a surprisingly long time, becoming an automated system in 1981 as System 4. This non cellular service was even expanded throughout the UK between 1982 and 1985 and continued in operation for several years, meaning it ran in parallel with the first cellular systems. Long distance calling As described above, one of the earliest demonstrations of a telephone call was actually quite a long distance, made by Queen Victoria from the Isle of Wight to London and elsewhere. But the first UK trial of long distance telephony as a commercial proposition was held on 1 November 1878, with a call between Cannon Street in London, and Norwich – a distance of 115 miles – using an Edison transmitter on a telegraph wire. For the first half of the 20th Century, long distance or 'trunk' calls – which effectively meant calls between any two towns or cities – could not be dialled directly by the caller, but had to be 'put through' by the operator. But a new era of fully automated telephony was ushered in at the end of 1958, when Queen Elizabeth II dialled a call from the Bristol exchange to Edinburgh, a distance of more than 300 miles – the most the system could achieve at the time. This was the start of Subscriber Trunk Dialling (STD). Before STD, Bristol subscribers could only dial directly to 2600 stations connected to 41 local exchanges just outside the city. Afterwards, they could make calls to 427 exchanges, including most of those in London, Birmingham, Manchester and Edinburgh. However, before STD could be introduced, telephone charges – which had been designed for manual operation – had to be simplified; only then could full automation follow. Group Charging Areas reduced the cost of most trunk calls: the Queen's call to Edinburgh lasted 2 minutes 5 seconds and cost 10d (4p); previously, the call would have cost five times as much. Satellite communications The first active, direct relay communications satellite was launched in 1962 – Telstar, which was famous enough then to have a hit pop single named after it! Telstar was operated as part of a multinational agreement between AT&T, Bell Telephone Laboratories, NASA, the UK Post Office, and the French National Post Office, to develop satellite communications. But early communications satellites were limited by not being in a geostationary orbit, which meant they moved across the sky and had to be tracked. Only when satellites could be placed in the geostationary orbits proposed in 1945 by science fiction writer Arthur C Clarke – where they orbited at the same angular velocity as earth – did the satellite communications breakthrough arrive. The first geostationary satellite, Syncom 3, was launched in August 1964 and used for communication across the Pacific, starting with television coverage of the 1964 Summer Olympics in Tokyo. Early Bird followed on 6 April 1965 and was placed in orbit at 28° west – the first geostationary satellite providing telecommunications across the Atlantic Ocean. Satellites have transformed many kinds of electronic communication, most notably tv, and satellite telephones can still be invaluable in remote areas. But, for mainstream global voice telephony, the impact of satellites has lessened because of huge improvements in submarine fibre optic cables and the vast bandwidth these offer. Not all satellite telephone projects have been successes – notably the projects to link large numbers of low earth orbit satellites in a constellation. Two of the most ambitious were Iridium and Teledesic. The latter, with backing from Microsoft entrepreneur Paul Allen, was to have more than 840 satellites. This was reduced to 288 and it ended up with just one test satellite being launched. Video telephony Just like mobile telephony, combining video with voice goes back farther than you might think. The world's first public video telephone service was developed by Dr Georg Schubert and opened by the German Post Office in 1936. The service linked Berlin and Leipzig using broadband coax cable – a distance of around 100 miles The system used mechanical tv scanning and 8in displays with a vertical resolution of 180 lines operating at 25frame/s. In 1956, AT&T developed a two way video telephone called the PicturePhone, enabling callers to talk while looking at a still picture that was updated every two seconds. It was demonstrated at the 1964 World's Fair in New York, but was not a success. Six years later, an updated service was offered to residents of Pittsburgh, but was eventually discontinued. Over the next few decades, various video telephony systems were tried – in 1971, for example, Ericsson made the first transatlantic phone call with its own video conferencing system. However, performance was typically poor because of limited bandwidth and huge costs – in the early 1980s, one system cost $250,000 to buy and offered dedicated lines costing $1000 an hour. UK consumers had to wait until 1993 for BT to launch a video telephony product. Relate 2000 featured a flip up colour lcd that could display the incoming video signal at a rate of 8frame/s. But, with lines offering a bandwidth of less than 3.4kHz, picture quality was poor and the device was not popular. Even so, it is still available today on sites like Ebay and can still be used.