at the junction of the Darling and Murray Rivers in Australia commemorating the time in 1956 when both rivers flooded and a fleet of little grey Fergies was used to build levee banks to save the town. A fleet of seven Ferguson TE-20s was used on the 1955–58 Commonwealth Trans-Antarctic Expedition which was led by Edmund Hillary. Four petrol-engined and three diesel models were used. Some were supplied as half-tracks, with steerable front skis, whilst others of the New Zealand team were fitted with an extra wheel on each side and full caterpillar tracks, developed by the expedition in the Antarctic. In both cases, the track kits were easily removable and in light conditions the tractors were used on standard wheels and tyres. A canvas cabin was added for windproofing. Other than this, the tractors were totally standard – two were even fitted with a standard farmyard hydraulic front-loader for loading and unloading supplies. Reports were made at regular intervals to the Ferguson company and these show the tractors to have been reliable and effective – being capable of climbing a 1-in-7 slope of "hard polished ice where a man cannot walk without crampons", as well as operating in conditions of −10 degrees Fahrenheit. Under Hillary these tractors were driven to the South Pole, becoming the first vehicles to be driven to the pole, and the first overland journey to the pole since Captain Scott. The tractors were left at the pole for the use of American researchers. One of the tractors used by Hillary's party was later repatriated to New Zealand and is on display along with other British Trans-Antarctic Expedition vehicles in the Canterbury Museum in Christchurch, New Zealand. One diesel (TEF-20) example, TEF320709 known as Betsy, earned a place in the Guinness Book of Records in May 2003 when Terry Williams drove it around the coastline of Britain, gaining the record for the longest journey undertaken by tractor. Betsy was donated to the Friends of Ferguson Heritage group in 2004, and can be seen on display at the Yorkshire Museum of Farming in York. In popular culture Between 1992 and 2015, a TEA-20 was depicted on the New Zealand five-dollar note. There was a portrait of Sir Edmund Hillary on the obverse (front), with one of the tractors used in his Commonwealth Trans-Antarctic Expedition at the bottom-left corner. A Ferguson tractor was also depicted on a New