 Morley also had interests in the extraction of china clay (a form of kaolinite) at Lee Moor, somewhat to the north-east of Marsh Mills, and he arranged with Johnson Brothers for them to extend the P&DR eastwards from Marsh Mills to Plympton, where the china clay could be brought down a pack horse road from Lee Moor.This opened in 1834.It is not clear whether the railway extension was Morley's property or the Johnsons', but it is generally regarded as being part of the P&DR.