Early county map (IMAGE) PNAS Nexus Caption Early county maps offer one of the richest and arguably most comprehensive cartographic sources of industrial location information for Britain in the late 18th to early 19th centuries. The study authors used over 140 early county maps made by an array of amateur and skilled mapmakers to identify the distribution of mill sites during the early Industrial Revolution. Watermills were often indicated on early county maps with waterwheel symbols (small circles with radiating spokes or vanes). Map source: Yates, W. 1786. The County Palantine of Lancaster, Surveyed by William Yates, Engraved by Thomas Billinge. Full map at https://maps.nls.uk/joins/10434.html. Credit National Library of Scotland Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.