Carolee:
   I think you mistakenly sent this message to me.  I just subscribed and
am not familiar with this subject.
Frank
Frank J. Millero, III                    E-mail: [log in to unmask]
Exploratorium                            Phone: (415) 561-0341
3601 Lyon Street                         FAX: (415) 561-0307
San Francisco, CA 94123