Markham Colliery daily tonnage and shifts worked book for Pit No.1 Arranged by sections for Blackshale, Ell Coal and Deep Hard. Columns for date, days worked, men on books, shifts possible, shifts worked, shifts lost, percentage voluntarily lost, output in tonnage, total percentage lost, tons per men, tons lost, total shifts underground, total per man underground, surface shifts, total shifts, total per man all employed, average earnings, surface lost and surface hands. Mar 1934-Jun 1940