E (Engineering) Tank Board -addenda to minutes including minute by WSC on Tank production; report by the Mechanical Warfare Department on the relation between man-power and tank production; Report by Admiral Sir Reginald Bacon on Zirconium Steel; minutes of Sub-Committee on Spares; report on trial of new Ford tank; report by James Maclean [Controller of the Mechanical Warfare Department] on Ricardo Engine production; report by Sir Albert Stern on Liberty Engines; report by Sir Ernest Swinton on the Ingles Heavy Tank Bridge; report by Sir Eustace Tennyson d'Eyncourt on the French Water Crossing Tank Carriers; reports from Tank Testing Field, Mechanical Warfare Depot, Newbury ; report on the medical aspect of Tanks by Major Lennox Broster, D.A.D.M.S., Tank Corps; report on Cleveland Caterpillar Tractors by Major-General John Headlam.