Geology of Great Britain 1830

This was a very interesting jigsaw to do. It shows coalfields as well as the main conurbations as they were in 1830. There are several differences with the geological map of today.
I did not do the white edges as they were almost impossible with no guidance to follow! There are also a couple of pieces missing in the centre, which is a mystery as I have only done it once before, and have never lent it out.