We are told by Theophanes in his “Chronography,” written 811-815, that in the year 673 an architect called Kallinikos[64] fled from Heliopolis in Syria to the Romans (_i.e._ Constantinople), and eventually compounded a “sea-fire” which enabled them to burn large numbers of the Moslem vessels engaged in the Seven Years’ War,[65] 671-677. This incendiary was again employed with success against the Moslems during their second attack against Constantinople, 717, and at the decisive naval victory over the Russians under Igor in 941. The evidence of Theophanes about Kallinikos is corroborated almost verbally by the Emperor Constantine VII., Porphyrogenitus, in Chap. xlviii. of his “Administration of the Empire”: “Be it known that under the reign of Constantine Pogonatus (668-685) one Kallinikos, who fled from Heliopolis to the Romans, prepared a ‘wet-fire’ to be discharged from siphons, by means of which the Romans burned the fleet of the Saracens at Cyzicus and gained the victory.”[66] It is true that when writing to his son (in Chap. xiii. of the same work) the Emperor gives (or tells his son to give) a different version of the invention of sea-fire: “If any persons venture to inquire of you how this fire is prepared, withstand them and dismiss them with some such answer as this—that the secret was revealed by an angel to the first Emperor Constantine” (A.D. 323-337).[67] But this passage only proves that the Emperor was mendacious and his people superstitious. There can be little doubt that this great invention was made by a Greek for the Greeks in the decade 670-680; but what was the nature of the mixture? All we know for certain about it is that it was a State secret, was intended for sea service, burned with much noise and vapour, and was projected from siphons. In other words, the mixture fulfilled the following conditions:— (1) Its composition could be kept secret. (2) It had some close connection with the sea, or water. (3) It burned with much noise and smoke. (4) It had some close connection with siphons, or tubes.