dockyards the perpetual construction of fleets numbering hundreds of vessels went on. For what purpose was this fleet got together, save for an attack upon the imperial city? There were signs in heaven, which meant, no doubt, disaster. A rainbow appeared for several days together in March; that was not without meaning. And there was an epidemic in Egypt which meant misfortune, at least to those who caught it. Had the Saracens been as prompt to execute as to conceive their design, there can be little doubt that Constantinople would have fallen, and the history of the East been anticipated by nearly six hundred years.
But one thing, besides this delay, saved the city. A Syrian, named Callinicus, escaped from the Saracenic rule, made his way to Constantinople, and imparted to the emperor a discovery which would multiply tenfold his powers of offence and defence, at least by sea. He had invented a projectile which could be used from ships or from walls—a projectile more destructive, more terrifying, less to be guarded against, than anything yet discovered by the brain of man. It was a fire of so subtle and dangerous a nature, that it would burn on the surface of water, under water, on the stones of walls, and the iron armour of men. It could not be extinguished: neither water, nor sand, nor earth, would put out this terrible fire. It could be projected at short distances through metal tubes, or even in little glass vessels, which could be used as hand-grenades; or it could be thrown by catapults and arbalists, a hissing mass of inextinguishable fire. The secret of this fire was well kept by
