I found this website the other day. It's brilliant for tracing old canals and railways.
http://maps.nls.uk/geo/find/#zoom=9&lat=52.6715&lon=-1.9318&layers=6&b=1&point=52.5447,-1.9510
I've found it better than
https://www.old-maps.co.uk
http://maps.nls.uk/geo/find/#zoom=9&lat=52.6715&lon=-1.9318&layers=6&b=1&point=52.5447,-1.9510
I've found it better than
https://www.old-maps.co.uk