Cover franked with Chilean 1938 40c emerald green and 1948 60c black (SG 272 & 379) tied by fine strike of boxed CORREOS DE BOLIVIA AMBULANTE No. 1 cancel in blue dated 26 JUN 1954. Addressed to SANTIAGO with blurred ANTOFAGASTA transit cds and SANTIAGO arrival cds's all on reverse. Chilean stamps were generally allowed on this section of the railway as it formed part of the line from Bolivia to the port of Antofagasta and then on to the rest of Chile.