Original: Before the Second World War maps were produced as a County Series at a scale of 6 inches to 1 mile (1: 10,560) and 1: 2,500 (25 inches to 1 mile).
Simplified: Before the Second World War, maps were produced as a County series at a scale of 6 inches to 1 mile (1:10,560) and 25 inches to 1 mile (1:2,500).