mooring at James Bay, depositing quantities of coal on the beach below the wharf. A census in 1921 showed the islands population was 3,747. The first islanders left to work at Ascension Island in 1921, which was made a dependency of St Helena in 1922. Thomas R. Bruce (postmaster 1898–1928) was the first islander to design a postage stamp, the 1922–1937 George V ship-design—this significantly contributed to island revenues for several years. South African coinage became legal tender in 1923, reflecting the high level of trade with that country. There were nine deaths from whooping cough between 1920 and 1929 and 2,200 cases of measles in 1932. The first car, an Austin 7, was imported into the island in 1929. A census in 1931 showed a population of 3,995 (and a goat population of nearly 1,500). Cable and Wireless absorbed the Eastern Telegraph Company in 1934. Tristan da Cunha was made a dependency of St Helena in 1938. Some six islanders gave their lives during World War II. The German battle cruiser Admiral Graf Spee was observed passing the island in 1939 and the British oil tanker RFA Darkdale was torpedoed off Jamestown bay in October 1941. As part of the Lend-Lease agreement, America built Wideawake airport on Ascension in 1942, but no military use was made of St Helena. As in the previous war, the island enjoyed increased revenues through the sale of flax. There were 217 cases of polio, including 11 deaths, in 1945. A census in 1946 showed 4,748 inhabitants lived on the island. In 1948 there were seven deaths from whooping cough and 77 hospital admissions from acute nephritis. In 1951, mumps attacked 90% of the population. Solomon's became a limited company the same year. Flax prices continued to rise after the war, rising to their zenith in 1951. However, this St Helena staple industry fell into decline because of competition from synthetic fibres and also because the delivered price of the island's flax was substantially higher than world prices. The decision by a major buyer, the British Post Office, to use synthetic fibres for their mailbags was a major blow, all of which contributed in the closure of the island's flax mills in 1965. Many acres of land are still covered with flax plants. A census in 1956 showed the population had fallen only slightly, to 4,642. 1957 witnessed the arrival of three Bahrain princes