Hornsbys bought a Rochet-Schneider car, powered by a petrol engine in 1906. It was fitted with a chain track and was trialled by the Army in November 1907 in Aldershot. The 4-ton vehicle achieved speeds of over difficult terrain. Hornsbys, in a rare moment of marketing "savoir-faire", commissioned a film of this vehicle to promote the virtues of the caterpillar track, which was to be shown at provincial and London cinemas in the summer of 1908. The film was first shown at the Empire Theatre of Varieties in Leicester Square on 27 April 1908, on a device then known as a bioscope. It was often of more interest than the actual film being shown, and is apparently the first film made for commercial purposes. Roberts was looking at increasing the speed of tracked vehicles. Hornsbys bought a Mercedes car and fitted it with chained tracks with wooden wheels to test a desert environment. Tests with this vehicle on Skegness beach in 1908–09 achieved speeds of ; such speeds with a caterpillar-tracked vehicle would not be surpassed until World War II. In 1910, Hornsbys sold four caterpillar tractors to the War Office—driving the first from Grantham to Aldershot. The tractors were used for towing artillery. Unfortunately, the officers in the Royal Artillery were not enamoured with the vehicle, finding it noisy and slow. One officer wrote, "The team of eight horses in my opinion is far superior under every condition."