At this time the British were using and were interested in a large tank only. The French had been using a medium-sized tank, known as the Schneider, but, as it had not been wholly successful, they had developed a much smaller two-man machine, called the Renault, which presented some very decided advantages and which they eventually adopted as their only type. While the large British tank had been reasonably successful in operation, it had certain very decided limitations which the British themselves recognized, so, after a thorough investigation of its possibilities and shortcomings, it was decided to redesign the large tank rather than to copy the existing model with its admitted defects. It was furthermore decided that the work of designing should be done jointly by British and American engineers, acting under the Anglo-American agreement drawn up as the result of a conference at British General Headquarters, which provided for the joint production by England and the United States of 1,500 large tanks, England to furnish the hulls, guns, and ammunition, the United States to provide the power-plant and driving mechanism. When the Armistice was signed, approximately 50 per cent of the work represented by the American components had been completed, and it was confidently expected that the entire programme of 1,500 would have been completed by March. England had about 250 of the hulls ready when the Armistice was signed. * * * * * The work of manufacturing the French type of tank had not progressed satisfactorily, however, this being partly due to the delay involved in changing all drawings from the metric system to the American, and to the difficulty which was experienced in inducing American concerns to take on the production of this machine, which is extremely complicated and difficult to manufacture. It was necessary, therefore, to divide up manufacturing activities on this tank between a considerable number of plants. The original programme called for 4,440 of these small tanks, of which 209 had been completed by the end of December, 1918, with 289 more partly completed and production just getting under way. There was every reason to believe that the entire number would have been ready for use by April, 1919.