-2- 3. Another such factor is concentration. At a time when the Government is finding it necessary to build up the man-power of th industry, I have found it necessary to maintain pit-room at as h### a figure as possible and to pursue a policy of intra-pit concentration rather than of transfer between pits. I estimate that the not yield of concentration, in terms of the output we should otherwise not have had, is about 20,000 tons per week, o### 1 million tons a year. 4. A serious factor involving loss of output in October has b###n the increase in disputes.