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Re: [Phys-l] How did Newton estimate the Gravitational constant?

BTW, Stong's Amateur Scientist (Sci. Am. Sept. '63)

gives instructions for a Mitchell torsion balance; it's large -- suspension 55" (#36 music wire**) arm, 41" weights (masses) 46 oz. juice can lead filled, and 100 gm. Both cylindrical -- like the recent rather more accurate one using W. Spheres are best, but diff. to accurately machine, no?



** I remember reading another one using 1/4" mag. tape.

bc notes included an electrostatic shield -- much larger constant!


On 2010, Oct 28, , at 10:39, Bernard Cleyet wrote:

Yes, and I think credit should be given to Michell who made the beta version of the balance and gave it (indirectly) to C. just before he (Michell) died.


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