Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

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.