Brick found in ballast at Reeking Gill on the Rosedale Mineral Railway (east section). From Castlecary, so a long way from home. https://www.scottishbrickhistory.co.uk/castlecary-fireclay-company-limited/ Castlecary operational late 19th century to 1930s, well after the railway was built in 1863-5, so presumably used as ballast repair during operation. Perhaps linked to Castlecary's Middlesbro' offices.