Signedon double block and tackle: B Martin London
FunctionThis instrument was designed to demonstrate the mechanical advantage that may be obtained with various arrangements of pulleys to lift or support weights and heavy loads.
Historical AttributesBenjamin Martin shipped this "Compleat Sett of Mechanicall Pullies with a Large square Frame in Mahogany, & brass hooks for hanging the Pullies on" to Harvard College on 28 September 1765. It cost £16.16.0.
Harvard professors used this apparatus to teach mechanics until the early 20th century, when class sizes and class rooms grew too large for everyone to see the small weights and pulleys.
Published ReferencesDavid P. Wheatland, The Apparatus of Science at Harvard, 1765-1800 (Cambridge: Harvard University Press, 1968), 86-87.