72. I wish to record by appreciation of the co-operation received from representatives of the National Union of Mineworkers and the British Association of Colliery Management, officials of the National Coal Board and workmen at Brookhouse Colliery and H.M. Inspectors of Mines in the North Eastern Division. I am particularly indebted to Mr. J. H. Longstaffe, H.M. Inspector of Mechanical Engineering and Mr. S. Luxmore. H.M. Electrical Inspector of Mines and Quarries, and also to Mr. E. W. Lane and other officials of No. 1 (Worksop) Area. for supplying technical information facilitating my investigation.

I have the honour to be, My Lord,

Your Lordship's obedient Servant.

A. E. Crook.