Ebay strikes again

**Bigwol** · 29-09-2009, 10:07 PM

I made the mistake of looking around eBay last week, and put in a silly bid for a W T Avery Balance which took my fancy. It turned up today.

It's a bit bigger than I had imagined, but is a thing of beauty complete with knife edge bearings. shining in gold lacquer on solid Brass

I'm going to make it a home on the shelf, but I'll need to raise the shelf above it by a couple of inches to make it fit. You think you've got your bench all tidy and then eBay sends more toys - Still, I'm sure it will come in handy.

**bustagasket** · 29-09-2009, 10:13 PM

very pretty!!!

**snow_imp** · 30-09-2009, 07:40 AM

Wow, I've never seen anything like it! And I can see why you bought it.

**MuranoSilver** · 30-09-2009, 09:14 AM

Oooh it's like "Steampunk" weighing!!

**Pandanimal** · 30-09-2009, 09:31 AM

very pretty.
But its not just for looking at is it?

**agent_44** · 30-09-2009, 09:31 AM

Yeah, very pretty, but do you plan on using it?

**Bigwol** · 30-09-2009, 11:14 AM

Originally Posted by agent_44

Yeah, very pretty, but do you plan on using it?

I certainly do - I found it as a result of reading the new edition of Gemstones of the World by Walter Schumann (ISBN 1-4027-4016-6)

Reading the section on Density and Specific Gravity, it explained the Hydrostatic balance method of determining the density of an unknown stone

Weight in air minus weight in water = volume

followed by

Weight in air divided by volume = density

The only straightforward way of weighing the stone in water involved using a traditional balance and a beaker of water - hence the original eBay search which turned up this splendid piece of kit for the princely sum of £14.50!

I'll let you know how I get on - trials scheduled for the weekend :-)

**agent_44** · 30-09-2009, 11:15 AM

Wow!!! Well, have fun with it, let us know how you get on!

**EmmaRose** · 30-09-2009, 02:02 PM

Lovely scales...can you tell what the stone is then, when you have the density?
Em

**Bigwol** · 30-09-2009, 04:49 PM

Yes

On Page 28 of the Gemstones of the World, there is a table Selected Gemstones Ordered by Density, which combined with what the stone looks like (and what you bought it as!) should give a pretty good idea of what it is, though I'm not an expert in it and would seek further advice if unsure.

Cheers

Dave