comprise a blend (in the proportion of 19:1 by weight) of anthracite and medium volatile coal (as to approximately 93 per cent of the total weight) and a cold-setting organic binder or a molasses and phosphoric acid binder (as to the remaining weight);

were manufactured from those constituents by a process involving roll-pressing;

are unmarked ovoids;

have an average weight of 160 grammes per briquette; and

have a sulphur content not exceeding 1.5 per cent of the total weight.