filled with water and had a fusible metal plug at the base. The case was heated, and when the plug melted the generated steam escaped and impinging on the air drove forward the projectile. The absurdity of the idea is too obvious to need discussion. The Duke carefully examined it, and after asking many questions, remarked: "If this had been invented first and gunpowder afterwards, what a capital improvement gunpowder would have been."
The great war saw these "inventions" multiplied a thousand-fold. The spread of education, the availability of books from which at least a smattering of any subject could be obtained, and from the increase both in quality and quantity of newspaper news a consequent closer knowledge of what was happening—all these factors helped to add to the crop of ideas. In many cases undoubtedly these ideas were elaborated and worked out by the inventor, adopted by the authorities, and proved of the highest value. These cases were, however, greatly in the minority, and were generally the work of one who had at least some pre-knowledge of his subject. Such a man was the late Wing-Commander F. A. Brock, R.N.A.S., of whom it can be said without fear of contradiction no one man did more for military pyrotechny during the great war, and possibly in no other single subject during the war was one man so invaluable.
Born in 1884, educated at Dulwich, he entered the firm of C. T. Brock and Co. in 1901, where he remained until the outbreak of war. Endowed with a marked inventive ability and a phenomenal memory, and brought up as it were in an atmosphere of pyrotechny, he developed a knowledge of pyrotechnic chemistry which was extraordinary and appeared almost instinctive.
A naval correspondent, writing in "The Navy," speaks of him as follows: "From H_{2}O to WO_{2} they knew all
