The necessity of reducing to a minimum the formation of scale on the heating surface of steam boilers if efficiency is to be maintained was referred to in an article in the Times Engineering Supplelrzent for September and in this connection Messrs. J. Dampney and Co., of Cardiff, Wales, draw attention to their "Apexior" compound a s a remedy against both scale and the pitting of the plates. The compound consists of 98 per cent pure amorphous carbon combined with a neutral organic vehicle.