A very long time ago scientific instrument makers were using quartz fibres. These were made from a piece of quartz heated to melting point with an oxy-acetylene flame on the bolt of a cross-bow which was discharged to draw out a quartz fibre that was very thin. Then experiments determining the gravitation constant and such like used this fibre to suspend items that were subject to tiny forces in torsion, the angular displacement being measured by light beams reflected off a suspended mirror. Quartz fibre has a long and distinguished history, and is a probably starter for the electrostatic gong instrument. Cheers, Neville Michie
> On 25 Jul 2019, at 06:22, Rob Klein <[email protected]> wrote: > > Really, I dunno WTF you're all on about. > > We are discussing an instrument built almost 200 years ago. > No PTFE, no optical fibers, no silicone oil or anything like that was > available back then! > Yet here's everyone falling over themselves suggesting 21st century > technology for something the people who built the original probably didn't > even think twice about. > > I'd still say waxed silk, as back then this was commonly used as insulating > material. But the catgut (actually mostly made from sheep intestines) > suggested earlier is also a strong contender. > > > Met vriendelijke groet, > Rob Klein > > verstuurd vanaf mijn smartphone > > Op 24 jul. 2019 20:21, om 20:21, ed breya <[email protected]> schreef: >> If you can find (or draw your own) pure polystyrene filament, that >> should work very well. Someone suggested optical fiber - this should >> work very well too, in the right conditions. You'd want bare glass >> fiber, with no protective plastic cladding, then thoroughly clean and >> treat it with a silicone oil like Dow 200. Glass isn't really all that >> great an insulator (in an extremely high impedance context), due to >> surface effects, so a silicone treatment helps a lot. >> >> Besides optical fiber form, just regular fibers of glass should be >> available, in different sizes and alloys. It may be hard to find it in >> small quantities though. >> >> PTFE should also be available in fiber form - somewhere - since it's >> used for making meshes, filters, separators, and screens for chemical >> process applications. Someone must produce the raw fiber stock that >> goes >> into these sorts of things. Again, finding it in small quantities could >> >> be problematic. It's best to use virgin PTFE if you go this route. >> >> Ed >> >> On 7/22/2019 11:16 AM, Dr. David Kirkby wrote: >>> I have been discussing with some friends about the Oxford Bell with a >> view >>> to making one. One guy can not believe a battery can last 175 years. >>> >>> Anyway, I was wondering what would make a good insulator to suspend >> the >>> ball. I thought of nylon fishing like, but can anyone think of a >> better >>> insulator? Obviously PTFE is a good insulator, but it’s not exactly >>> flexible. Nor is sapphire. >>> >>> Dave >> >> >> _______________________________________________ >> volt-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com >> and follow the instructions there. > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.
