GUGLIELMO MARCONI (1874-1937) Italian physicist and inventor of wireless telegraphy. A superb I.S.P. "Guglielmo Marconi ", 5 1/2" x 9" b/w, an oval profile portrait of the great inventor inscribed in Italian to Sabelli and mentioning Sabelli's New York/Rome flight, dated August 13, 1934. Fine condition, loosely set into a period frame. Sabelli was the first to transmit a wireless message from an airplane in flight, sending Marconi, then in London, his greeting: "...as we retrace the steps of Columbus...by means of invisible radio strands we are enabled to maintain our contact with the world at sea and ashore as we blaze a new air trail...".  $1,000-$1,500