April 1992 For the meeting of April 21, 1992 Calvet M. Hahn gave an hour long presentation on cross-border mails involving stampless covers.  He began with 14 slides showing various rarities, most of which were subsequently passed around.  He then moved into Part I of the program, passing around a series of covers relating to transportation methods used on cross-border mails—steamboat, railroad and express company covers. Picking up from his chapter on Inland Waterways in his 1970 book Ess...