Thanks to Henry Grunder for the tip. I found Percival Scientific on the
Thomas Register Website. (Registration is required for use -- free and
relatively painless). For those who had asked, Percival is in Boone, Iowa
50036; phone (515) 432-6501 fax (515) 432-6503.
Thanks again, Henry!
Eugene Dillenburg
Geology Department
The Field Museum FAX: 312-922-9566
Roosevelt Road at Lake Shore Dr. phone: 312-922-9410 ext. 293
Chicago, Illinois 60605
"It's not really food if it doesn't hurt."
-- Bruce Elliott