director, David Roberts: the track was patented in July 1904. The following year Roberts demonstrated his tractor unofficially to the British Army's Mechanical Transport Committee, with a formal demonstration staged at Grantham in February, 1906, at which the machine outperformed a conventional wheeled tractor. A lightweight version of the tracks was also fitted to a Rochet-Schneider motor car. In July 1907, an improved chain track was demonstrated at the British Army's HQ at Aldershot. Roberts explained that he had plans for a trailer, also fitted with a chain track, on which a gun could be mounted. Roberts completed his tracked trailer and demonstrated it to the Royal Artillery in November of the same year. Holt Company photographer Charles Clements was reported to have observed that the tractor crawled like a caterpillar and Holt seized on the metaphor. "Caterpillar it is. That's the name for it!" There was a further demonstration at Aldershot in 1908, at which King Edward VII was present. The tractor and trailer with dummy gun in place are considered to have performed impressively, crossing various types of obstacles and ground, and the demonstration became national news. A horse team that became bogged down was easily hauled out of the mud by Roberts's machine. The Mechanical Transport Committee was amongst those that considered the system to have great potential. A newspaper suggested that this was "the germ of a land fighting unit when men will fight behind iron walls". Roberts was awarded a £1000 prize from the War Office for his machine's performance in travelling without stopping. A third machine was tested at Aldershot in May 1910, and towed a 60-pounder gun and its ammunition over rough ground. It was here that Major W. E. Donohue of the Mechanical Transport Committee suggested to Roberts that a single tractor unit might be fitted with a gun and bulletproof shields, thus creating some sort of self-propelled gun. Roberts did not pursue the idea, and later expressed regret at not having done so. A further trial took place in North Wales. After contests between the No. 3 machine and horse teams, artillery officers gave a less favourable opinion of the tractor, observing that it was underpowered. An attempt was made to remedy the problem by converting it to run on petrol, a move that increased the brake horsepower to 105. The Mechanical Transport Committee remained convinced of the tractor's possibilities, provided