Generally speaking, foreign bills of exchange resemble domestic bills of exchange. Foreign bills, however, have two features which domestic bills do not have. First, there is the necessity of converting one standard of money into terms of another standard - that is, a bill drawn in dollars payable in London, for example, must have its amount changed to pounds sterling. Second, the length of time required and the expense involved in shipping gold from one country to another are usually greater than would be the case within a country.