Butterley Company correspondence file of J. G. Belfitt, Mining Agent, with J. Cox of the Planning Department, regarding the Butterley collieries Including internal correspondence on colliery plans, water levels in shafts, pumping at Denby Hall Colliery, Dec 1943-Feb 1945, information on Ironville borehole, Mar 1944, development of working the Piper Seam at Britain and New Langley collieries, May 1944, Planning Department monthly report, May 1944, schedules of belts and structures in use at collieries, Oct 1944, diagrammatic sketch of working and connecting drifts at Pentrich Colliery, Mar 1945, plan of proposed lavatories at Langley Office, Mar 1945 and plans of alterations to accommodation for medical requirements at Ormonde Colliery, Mar 1945 Jan 1943-May 1945