The Hughes simplex and duplex apparatus is chiefly used for cable working. Some of the Hughes duplex circuits not infrequently deal with 150 telegrams hourly, and even this number has been exceeded. A Baudot circuit working four “arms” has at times of pressure disposed of from 250 to 300 telegrams in an hour. The annual daily traffic in telegrams to and from the Continent about the year 1870 was between 4000 and 5000: at the present time it is from 24,000 to 26,000 telegrams. In addition to this, some 3500 telegrams are daily handed over to the cable companies, with whose offices in London there are connecting pneumatic tubes. Now to deal successfully with the vast amount of telegraph traffic which passes throughout the United Kingdom and to and from the Continent it is of course essential that there should be one large depôt to act as the chief transmitting centre. This is naturally London, the capital of the British Isles. The first Central Telegraph Station was established about the year 1850 by the Electric Telegraph Company in Founder's Court, Lothbury. In 1860 larger premises were built in Telegraph Street, just off Moorgate Street, E.C., and at the time of the transfer, and up to January 1874, this building remained the Central Office. The rapid extension of business soon made a move necessary, and the staff and wires were transferred in 1874 to the new building in St. Martin's le Grand. It was thought that the spacious third floor in that building would be more than sufficient for that purpose for many years, but at the present time almost every portion of the big building is devoted to telegraphs.