On Mon, 18 Mar 2013 20:18:26 +0000 (UTC), Cydrome Leader
wrote:

Spehro Pefhany wrote:
On Mon, 18 Mar 2013 15:54:19 -0400, Bob Engelhardt
wrote:

35 lb tungsten "ballast" blocks (race cars): $1877

http://www.stockcarsteel.com/tungsten/

Twice as dense as steel & 50% more than lead, but what a price to pay
for the little space that it saves.

We've got a block of tungsten that pretty much fills up the inside of
a little plastic Pelican case. It's funny watching people do a
double-take when they pick it up.

What's it for?

Testing a gravitational sensing instrument, so something close to a
point mass is useful.