The Royal Naval Experimental Station at Stratford, of which he was in command and which he organised and brought into being, had many activities besides smoke. But even the exacting work of controlling its many activities was not sufficient for the Commander’s untiring energy; the few moments he could snatch from his duties and the many he stole from sleep were devoted to the invention and elaboration of war devices. His greatest achievement was the Brock anti-Zeppelin bullet, for which he and he alone is responsible, and which beyond any shadow of doubt delivered this country from the terror of the Zeppelin raids. His other inventions include many purely pyrotechnic smoke devices and inventions connected with the production of smoke, such as igniters which were used to start the action of smoke production, the Dover flares of one million candle power each, used by the anti-submarine patrol in the Straits of Dover, and burned to the extent of several hundreds every night. He was also responsible for several forms of stars for use in Very pistol cartridges. Captain Carpenter, V.C., in his splendid book, “The Blocking of Zeebrugge,” writes as follows of his work in connection with that operation: “It would be difficult for anybody to speak too highly of Wing-Commander Frank A. Brock. He was a rare personality. An inventive genius, than whom the country had no better, it was his brain that differentiated this blocking enterprise from all previous attempts in history in one most important particular. The difficulty of reaching the destination in the face of a strenuous opposition had hitherto brought failure, but he provided an antidote in the form of a satisfactory artificial fog designed to protect the blockships from the enemy’s guns during the critical period of approach. That in itself was a wonderful achievement, but his inventive mind was not satisfied therewith. To him we owed the special flares intended for turning darkness into light.