 Testing was performed two days later and supplies of granite started to arrive at the Road Research Station for more trials.Terrell’s choice of the Road Research Station for a firing range was convenient, as they had all the necessary experience with dealing with stone and bitumen – yet in his memoirs, Terrell insists that the original choice was simply good fortune.Terrell coined the term "plastic armour" for his invention, partly because it was plastic in the sense of being malleable and ductile while hot but also because he thought that the term might be confusing to German intelligence, who might assume that the product was made with the synthetic wood plastics then available.