H. E. Merritt

From 1945 he was a manager in the agricultural division of Morris Motors and from 1949, chief research officer at the British Transport Commission.

[6][7] The system also allowed a tank to perform a neutral turn on the spot by rotating its tracks in opposite directions.

[8] The greater manoeuvrability provided by Merritt's invention made British tanks more suited to the faster pace of warfare seen in the early Second World War in France and Poland which contrasted with the more static trench warfare of the First World War for which inter-war British tanks had been optimised.

It was a field in which "the physicist has so far played little part" and in which the practitioner "gropes dimly in the fog" relying mostly on empirical methods supplemented by elementary trigonometry and algebra that tended to give a deceptive authority to what was often little more than educated guesswork.

By the time of the third edition of Gears in 1954, knowledge had moved on somewhat but Merritt was obliged to admit that empiricism still ruled and that "the behaviour of mating tooth surfaces and their lubricant still awaits a full understanding.

[17] Writing about Merritt's 1947 book on gear trains for American Scientist in 2000, Brian Hayes paid tribute to the surprising amount of interchange between mathematics and mechanics evident in the work of Camus, Brocot, and Merritt, but observed uneasily that the power of the electronic computer had "put the gearmakers out of work" as all practical combinations in a gear train could now be calculated in seconds using brute-force techniques so that it was "hardly worth the bother of being clever".