1902, June 10: URUGUAY to BUENOS AIRES
5c envelope with 5c URUGUAY stamp, directed MERCEDES, a small Argentinian town 
located at the mouth of the Uruguay River, where struck with 
ESTAFETA FLUVIAL DE CORREOS / ENTRE MERCEDES Y BOCA DEL YAGUARY 
river boat mail cancel and oval barrel E/32 on adhesive. Received BUENOS AIRES, June 11.

ONLY KNOWN FOREIGN USAGE


1900, November 22: BUENOS AIRES to MONTREAL, CANADA
Uprated with 7c adhesives for Single Outbound Rate, endorsed in manuscript 
"For vapor Magdalena / via Rio de Janeiro".
Backstamped NEWYORK, December 27.

RARE DESTINATION FOR THE PERIOD


1900, SEPTEMBER 11: BUENOS AIRES to LONDON
12c Blue single outbound rate envelope, re-addressed upon arrival
and mailed on October 8 with 1p Victoria adhesive.