Nice visit this morning from map collector John Hancox, who is decluttering and kindly delivered a selection of relevant historic local maps to the door.

Based on surveys from the 1880s showing buildings, springs, field boundaries, antiquity sites and trigpoints the maps date from the 1930s to the 1970s. It’s beautiful detailed work, not made easier by the transition from traditional measures to decimal. As the 1930s maps note:

“to convert decimal parts of an acre into roods and perches you multiply by four to give roods and decimals of a rood, multiply this decimal by 40 thus obtaining Perches and Decimals of a Perch.”

You can see why they needed slide rules. By the 1970s the maps are fully decimal and metric. Selected details below…

The 1931 edition is 1:2500 scale, which is 25.344 inches to a statute mile, it says, or 208.33 feet to the inch.

Another 1931 map to the same scale. Every field is numbered, and acreages are given to three decimal places.

The smaller 1961 edition: 6 ins to the mile and contour lines in feet.

By 1972 it’s a 1:10,000 metric edition. This shows the Kelston Roundhill trig point at a height of 218 metres above sea level.