The major problem with the heat storage system was the difficulty in controlling the reaction that released the heat. Maths, physics, chemistry and mechanical engineering combined forces and assaulted it vigorously, but a solution continued to elude the team. They did succeed in modifying the compound so that it was less prone to break down into unstable components, but Peter’s ‘box’ seemed as far away as ever. John’s feeling that the solution was on the tip of his tongue faded slowly, and this enabled him to stop thrashing about mentally and to apply himself methodically and patiently. But all avenues of endeavour seemed to reach the same dead end. There were times when John became very dispirited and he had difficulty in keeping it from the others. Brian Gerard could usually be counted o
