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At 12:37 PM 2/15/2007, BC, you wrote:
Here's another from Sci. Am. (Sept. 1963)
"An inexpensive version of the Cavendish apparatus, modified to include
electrostatic shielding, has been constructed and used successfully for
evaluating G within 1 per cent of the currently accepted value by Sam
Epstein of Los Angeles.
Figure 3: Lower end of suspension
Epstein writes: "Essentially the Cavendish apparatus is a sensitive
torsion balance and a balance arm suspended at the middle by a slender
steel wire. ////
Bah, humbug! This may be Epstein's Cavendish apparatus,
but Cavendish's Cavendish apparatus was slung initially from
a silvered copper wire of about 10 thousandths inch diameter.
Details...details! :-)
<http://books.google.com/books?vid=OCLC27796316&id=zrkEAAAAMAAJ&pg=RA2-PA125&lpg=RA2PA125&dq=cavendish+experiment+suspension+wire#PRA1-PA67,M1>
page 67
a silvered copper wire, 39 1/4 in long, weighing 2 4/10 grains/ft.
bc
Brian Whatcott wrote:
...
Now that WAS a physics setup. Torsion to spare in fact.
Which reminds me that I seem to recall that Cavendish discarded
his first copper torsion wire as too compliant, allowing the arm
to hit the draft-box.
Brian Whatcott Altus OK Eureka!
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