ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
*****************************************************************************

We have been using a #50 steel grit from McMaster Carr 3165K15 
(www.mcmaster.com) in our traveling magnet exhibits. It is coarser 
than the black iron sand we use on the floor and is really clean. It 
has a nice feel to it as well and shows the lines of force more 
clearly than small washers or ball bearings.

I'll offer a bit of caution about steel spheres. If you have the 
exhibit on a hard floor, the spheres make a really nasty slip hazard.

-- 
Kua Patten MFA
Acting Director
Exploratorium Exhibit Services
3601 Lyon St.
San Francisco, CA 94123
Phone; 415-353-0409
Fax; 415-353-0433
www.exploratorium.edu

"Chaos demands to be recognized and experienced before letting itself 
be converted into a new order"
Hermann Hesse

***********************************************************************
For information about the Association of Science-Technology Centers and the Informal Science Education Network please visit www.astc.org.

Check out the latest case studies and reviews on ExhibitFiles at www.exhibitfiles.org.

The ISEN-ASTC-L email list is powered by LISTSERVR software from L-Soft. To learn more, visit
http://www.lsoft.com/LISTSERV-powered.html.

To remove your e-mail address from the ISEN-ASTC-L list, send the
message  SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]