on the official Italian navy chart. Marconi continued to experiment, concentrating his efforts on the short wave spectrum. In April 1923, he sailed from Falmouth to the Cape Verde Islands and monitored signals from the station at Poldhu in England, which was operating on a wavelength of 97 metres with a power of 1 Kw. It was noted that the signals disappeared at a distance of 2594 km (1400 nmi.) but at night-time they could be heard at 4632 km (2500 nmi.). In 1924 thanks to an improved aerial at Poldhu, two-way communication from the yacht was established from the Mediterranean and the Atlantic on a wavelength of 32 metres. The same experiment also proved successful, with solid signals throughout the day, when Elettra was in port at Beirut. Another successful contact was made from the yacht (in the Mediterranean) to Sydney enabling Marconi to speak to the managing director of the Amalgamated Wireless Company. These experiments using beamed transmissions convinced the British government of the viability of shortwave (as opposed to the current use of longwave) and resulted in a contract with Marconi's company for a communications network, the Imperial Wireless Chain, linking stations in the British Empire with London. In 1926 a two-way communications link was officially inaugurated between Britain and Canada. Elettra was in British waters in September 1925 when, during a run from Dover to Southampton, Marconi demonstrated the use of wireless for direction finding. On a wavelength of 6.09 metres, bearings were taken on a transmitter on the lighthouse at South Foreland. The receiving aerial on the yacht was a 2-foot length of wire suspended at one end of the bridge and reception was possible at a distance of up to 100 miles. In 1929 the wireless equipment aboard Elettra, which had been fitted in 1923, was replaced by technicians from Marconi's company with an updated and improved installation. Early in 1930 wireless telephony contact was made with Amalgamated Wireless (Australasia) in Sydney and on 26 March of that year, Marconi achieved publicity worldwide when, by pressing a Morse key on his yacht in Genoa harbour, he remotely switched on the lights in Sydney for the opening of the World Exhibition. Further experiments were conducted off the Italian coast in the 1930s on a wavelength of 57 cm using wireless telephony. In 1931 Elettra completed a round-the-world voyage. On 30 July 1934, with a 60