ABSTRACT
The limited extent to which a machine culture had yet taken hold may be inferred from an N.C.B. Information Bulletin published towards the end of the research period (No. 58/194, 1958), which gave the mean o.m.s. of mechanized faces as 5·6 tons, against a national average of 3·3. This is within the upper limits of the partially mechanized range and may be taken as a gross indication of the extent to which new machines were being used in a manual context.
