Consul, the Educated Monkey
Consul, the educated monkey, is a mathematical toy calculator patented by William Robertson in 1916 and made by the Educational Novelty Company of Dayton, Ohio, USA. This is an early example of mathematical toy. When each of the monkey's feet are moved to point at two numbers, the monkey's hands move to indicate their product. Play with the following Java applet to see how it works (you can download it from www.rechenwerkzeug.de).


 










This tin toy can be translated into a bar-and-joint framework. This translation allows us to construct our own "monkey" linkage similar to Consul using paper and paper fasteners. See, for the details,

S.J. Kolpas and G. R. Massion, "Consul, the educated monkey," Mathematics teacher, Vol. 93, No. 4, p. 276, 2000.