country mile

The story

Often ascribed to the fact that a mile walked in the countryside may appear longer than a mile in built-up areas as visual impressions are less varied. However, texts from the 18th century (see citations page) attest the use of (other) country miles as an umbrella term for miles other than the imperial English mile. This use provides a more plausible explanation of the sense because some continental European miles were considerably longer (e.g., 1 Prussian mile equalled about 4½ imperial miles).