Multi-wheeled machine tests road surfaces at Ministry of Transport laboratories. In the search for improved road surfaces and, incidentally, road safety, the Ministry of Transport has many intricate machines at its Road research laboratory in Harmondsworth, Middlesex. One machine has 19 wheels and incorporate a revolving drum. The machine is taken over a stretch of road and records on the drum a graph of every irregularity in the surface. Photo shows, inflating the wheels of the road testing machine at the laboratories. Each tyre has to be inflated to an identical pressure. 30 November 1937