Thailand. (Trans-Pacific Mail via Hong Kong). 1940. Air Mail envelope addressed to the United States bearing SG 242, 25s blue (pair), SG 244, 1b green and lilac and SG 287, 5s lilac (strip of three) tied by Bangkok GPO date stamp '23rd Aug 40', endorsed 'Per Trans Pacific Airline via Hong Kong'.
Nice franking paying 1 baht 65 satang carried 'B.O.A.C.' to Hong Kong and across the Pacific by 'P.A.A.' clipper.