Headed 'SCADTA Apartado 208 Barranquilla Rep. De Colombia' cover with blue 'IMPRESOS' marking sent at the unsealed rate franked with only a single 1917 1c green (SG 358) tied by BARRANQUILLA SCADTA cds with additional BARRANQUILLA Agencia Postal transit cds on front. Addressed to USA with fine strike of 'Use the Colombian Air Mail ! It saves you 18 Days Information, Stamps through American Trading Co. 25 Broad Street, New York' American consular agents cachet in blue on reverse. Mail from Scadta offices & employees was exempt from payment of the airmail fee.