The next day (April 5th) King Leopold invited him to a private interview at the palace. Accompanied by Mr. Sopwith, he proceeded to Laaken, and was very cordially received by His Majesty. The king immediately entered into familiar conversation with him, discussing the railway project which had been the object of his visit to Belgium, and then the structure of the Belgian coal-fields,—his Majesty expressing his sense of the great importance of economy in a fuel which had become indispensable to the comfort and well-being of society, which was the basis of all manufactures, and the vital power of railway locomotion. The subject was always a favourite one with Mr. Stephenson, and, encouraged by the king, he proceeded to describe to him the geological structure of Belgium, the original formation of coal, its subsequent elevation by volcanic forces, and the vast amount of denudation. In describing the coal-beds he used his hat as a sort of model to illustrate his meaning; and the eyes of the king were fixed upon it as he proceeded with his interesting description. The conversation then passed to the rise and progress of trade and manufactures,—Mr. Stephenson pointing out how closely they everywhere followed the coal, being mainly dependent upon it, as it were, for their very existence. The king seemed greatly pleased with the interview, and at its close expressed himself obliged by the interesting information which the engineer had communicated. Shaking hands cordially with both the gentlemen, and wishing them success in their important undertakings, he bade them adieu. As they were leaving the palace Mr. Stephenson, bethinking him of the model by which he had just been illustrating the Belgian coal-fields, said to his friend, “By the bye, Sopwith, I was afraid the king would see the inside of my hat; it’s a shocking bad one!” Little could George Stephenson, when brakesman at a coal-pit, have dreamt that, in the course of his life, he should be admitted to an interview with a monarch, and describe to him the manner in which the geological foundations of his kingdom had been laid!