I did a pipedia search and a Google but found nothing that clearly explained what a reverse calabash is. I've seen pictures and I can figure out what makes a pipe a reverse calabash.
shank calabash
I've thought this all along. I don't think moving the chamber a quarter inch up or down the smokestream really matters. The geometry is a little different, but I'm not sure they smoke would be able to tell the difference.Wouldn't Peterson's system also be considered a form of a reverse calabash?