Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Measuring the Gravitational Constant, G
A demonstration/lab idea for determining the numerical value of the universal gravitation constant using a torsion balance.
Wikimedia
Wikipedia: Henry Cavendish
Wikipedia offers biographical information on the British scientist Henry Cavendish (1731-1810), credited with having discovered hydrogen, which he described as "inflammable air."
Physics Classroom
The Physics Classroom: Cavendish and the Value of G
A short description of how Cavendish measured the value of G - the universal gravitation constant and supported Newton's theory. Illustrated.