I have missed the conversation concerning "galton quincunx", but the
last message appears to me that someone is looking for a bell shaped
curve demonstration.  Besides binning the grades of my students' last
exam, I have seen two rather nice ones - one small at Acton Science
Museum in Acton, MA and one rather large at teh Science Museum in Boston.
I didn't see one at Boston Children's when I was there a few months
ago, but may have missed it.  Cheers, Brian Holton, Rutgers Univ. Physics