SALESMAN  AND  CUSTOMER  265
are  found  for  example  in  Colombia,  at  Barranquilla,
  Savanilla,  Santa  Marta,  and  along  the
seaboard.  It  is  unwise  to  send  mail  in  care  of
the  General  Delivery.  Later  on  after  you
have  been  over  the  territory  and  established
friendly  relations  with  some  dealer  or  merchant, ­
  mail  may  be  sent  in  his  care.
Passports  are  unnecessary  in  Latin  America.
Funds  should  be  carried  in  the  form  of  Letters ­
  of  Credit.  It  is  wise  to  take  one  of  these
in  Dollars  and  Cents  and  the  other  in  Pounds
Sterling,  as  there  will  be  many  opportunities
to  use  one  of  these  advantageously  in  selling
exchange  when  the  other  cannot  be  so  employed. ­
  This  all  depends  of  course  on  the
local  demands  for  foreign  exchange,  and  before ­
  buying  money,  it  is  wise  to  ascertain
which  letter  of  credit  can  be  used  more  profitably. ­
  The  saving  which  can  be  made  in  the
course  of  a  long  trip  in  closely  watching  the
price  of  money  and  buying  when  conditions
favor  you,  is  worthy  of  your  best  attention.