James Ferguson's crane, 1764-1776.
© Science Museum / Science & Society Picture Library
Model. James Ferguson (1710-1776) devised this crane in 1764 to overcome two problems: the disastrous effects of letting the load drop in a common crane, and the inefficiency of raising a small load with an unnecesarily large mechanical advantage. Ferguson stated that his crane could be installed in a room 8 feet square.