E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
The weight of certain parcels of gold in the mint. A journey of gold is fifteen pounds Troy, which is coined into 701 sovereigns, or double that number of half-sovereigns. A journey of silver is sixty pounds Troy, which is coined into 3,960 shillings, or double that number of sixpences, half that number of florins, etc. So called because this weight of coin was at one time esteemed a days mintage. (French, journée.)