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

[Bernard Cleyet <bernardcleyet@redshift.com>]

This** and vibration are important.   Our Leybold pendulum was on a concrete slab whose legs were set in a sand box.  The box on wet suit rubber.  ***

**  One of my workers did the experiment (for fun) at his Santa Cruz mountain residence -- rock stable till the sun hit it!   He did three years of postgraduate work in Baume and Bordeaux.  He now manages his father's winery and vineyards in the Napa Valley.

*** Advice from a pro. recdng. engineer for isolation of mich. stands

bc

p.s. We tried the app. on the concrete ground floor, and found it totally unsatisfactory, as the HV system on same slab.  The first floor, tho. post and lentil construction,** afforded considerable isolation.

** Not the best!  in earthquake country -- The engineers claimed another half min. or so shaking woulda resulted in failure.  Considerable spalling at the post lentil joints.  Very over designed (my opinion) steel buttresses were added at great expense, but less than razing and rebuilding.  I signed a waver to enter building to recover apps. to set up a temp. Lab in the new partially occupied bio. building.  Huge wooden posts were added next to the concrete ones incase of aftershocks, etc.   [Remember: construction wood has a higher specific strength than the usual construction steel.]

On 2010, Oct 29, , at 10:14, brian whatcott wrote:

>  - a basement store room set in a limestone stratum which provides a 
> rather stable temperature.