SCHEDULE AUTHORISED FUELS
35 Sovereign briquettes, manufactured by Monckton Coke & Chemical Company Limited at Royston, near Barnsley, South Yorkshire which—
(a) comprise anthracite (as to approximately 75 per cent of the total weight), coal and reactive coke (as to approximately 21 per cent of the total weight) and cold-setting resin binder (as to the remaining weight);
(b) were manufactured from those constituents by a process involving extrusion;
(c) are unmarked hexagonal briquettes and have an average weight of 130 grammes; and
(d) have a sulphur content not exceeding 2 per cent of the total weight.