Title | Miscellaneous notes, calculation and diagrams, including: Gwalia Colliery shaft details Mynydd Newydd seams Depths of seams in Swansea neighbourhood Diagram of beam winding engine at Pentre Colliery Diagram of beam winding engine with double cylinder engine at Mynydd Newydd Pit Gorwydd New Pit strata Notes from 'Grandfathers field book' |