A model of a prehistoric icthyosaurus is dragged from its pond in the grounds of Crystal Palace, London, for its annual clean. The 'keeper' is being helped by some of the local police force. (Photo by Fox Photos/Getty Images). February 1927

Exhibition staff give a prehistoric model its annual clean in the grounds of Crystal Palace in London. (Photo by Fox Photos/Getty Images). 26th January 1930

A model of a prehistoric animal at Crystal Palace, London, is given its annual scrub by one of the exhibition staff standing on its back and using a broom. (Photo by Fox Photos/Getty Images). February 1927

Exhibition staff give a prehistoric model its annual clean at the grounds of Crystal Palace, London. (Photo by Fox Photos/Getty Images). 26th January 1930

Michael Redgrave (1908 – 1985) and Phyllis Calvert (1915 – 2002), the stage name of Phyllis Bickle. They are at a dinosaur exhibition in a scene from the film “Kipps” about a drapers assistant coming into money. The film was directed by Carol Reed for 20th Century Fox. (Photo by Hulton Archive/Getty Images). Circa 1941