Cover with typed 'VIA PANAGRA' at top franked with block of four 1928 5c scarlet 'Artigas' issue (SG 548) tied by MONTEVIDEO cds dated 29 XI. 1929. Flown on the Montevideo - Buenos Aires - Santiago - Miami first flight with triangular 'PRIMER VUELO POSTAL URUGUAY - ESTADOS UNIDOS' first flight cachet in green. Addressed to USA. Two tape marks on reverse. (Muller #31)