Many years ago I saw a picture of a huge set of wheels that was used to remove tree stumps during the construction of the Erie Canal (1817–1825) and was intrigued by its use of leverage, mechanical advantage, and torque. Figure 1 is a scale model of the device based on my memory of the (lost) picture and published accounts.1 

Topics
Bioacoustics of mammals, Friction
1.
Noble E.
 
Whitford
,
History of the Canal System of the State of New York
, Vol.
1
, (Albany, NY,
1906
), p.
91
.
Google Scholar
 
© 2013 American Association of Physics Teachers.
2013
American Association of Physics Teachers
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