Thevenot (Travels in the Levant), says, that in the 52d year of the Hegira, (Anno Domini 672), Constantinople was besieged in the reign of Constantine Prognates, by Yesid, the son of Moavia, the first caliph of the family of the Ammiades; when the Greek emperor found himself so pressed, that he was almost reduced to despair. But the famous engineer, Callinicus, invented a kind of wild fire, which would burn under water, and by this means destroyed the whole fleet.
Gibbon (History of the Decline and Fall of the Roman Empire, vol. vii, p. 282), speaks also of the Greek fire, and observes, that the deliverance of Constantinople may be chiefly ascribed to it. It appears, that Callinicus, the inventor, deserted from the service of the Caliph to that of the Emperor; and Gibbon is of opinion, that this discovery or improvement of the military art, was fortunately reserved for the distressful period, when the degenerate Romans of the east were incapable of contending with the warlike enthusiasm and youthful vigour of the Saracens. He is of opinion, that little or no credit can be given to the Byzantine accounts, as to the composition of this fire; although, from their obscure and fallacious hints, it should seem that the principal ingredient was naphtha, a liquid bitumen which springs from the earth.[39] This was mixed with sulphur, and with the pitch, extracted from the evergreen firs, according to the testimony of Anna Commena, (Alexid, l. xiii, p. 383), and Leo, in the xixth chapter of his Tactics, speaks of the new invention.
Gibbon describes its effects much as we have stated, viz. that the fire was strong and obstinate, and was quickened by water; that sand, urine, and vinegar were the only agents that could damp its fury; that it was used for the annoyance of the enemy, both by sea and land, in battles or in sieges, and was either poured from the rampart in large boilers, or lanched into red-hot balls of stone and iron, or darted in arrows and javelins, twisted round with flax and tow, which had deeply imbibed the inflammable oil; that, at other times, it was deposited in fire ships, or blown through long tubes of copper, fixed on a prow of a galley; that its composition was kept secret at Constantinople, pretending that the knowledge of it came from an angel to the first and greatest of the Constantines, with a sacred injunction not to divulge it under any pretext, &c. He also observes, that, after it was kept secret above four hundred years, and to the end of the 11th century, the method of preparing it was stolen by the Mahometans, who employed it against the crusaders. A knight, it appears, who despised the swords and lances of the Saracens, relates, with heartfelt sincerity, his own fears, at the sight and sound of the mischievous engine, that discharged a torrent of the Greek fire, the feu Gregeois, as it is styled by the more early of the French writers. "It came flying through the air," says Gibbon, quoting Joinville, (Histoire de St. Louis) "like a winged long tailed dragon, about the thickness of a hogshead, with a report of thunder and the velocity of lightning; and the darkness of the night was dispelled by this deadly illumination. The use of the Greek, or as it might now be called, Saracen fire, was continued to the middle of the 14th century, when the scientific or casual compound of nitre, sulphur, and charcoal, effected a new revolution in the art of war, and the history of mankind."
Ramsay, our learned historian, (Universal History, vol. ii, p. 150), gives the same account of the Greek fire. Morse, in his Universal Geography, page 588, observes, that naphtha forms springs in Persia, and, when scattered on the sea, it burns, and the flame is often wafted to a great distance.
For remarks respecting the naphtha of Persia, and the universal fire of the followers of Zoroaster, see the article on [Naphtha.] In naphtha districts, the quantity of inflammable air is so great, that it is used for fuel.
Since writing the above, we have examined Ruggeri, (Pyrotechnie Militaire, p. 289), and find nothing new. He states the composition of Greek fire, on the authority of others, to consist of naphtha, sulphur, bitumen, camphor, and petroleum; that it was invented by Callinicus, and employed against the Saracens as an incendiary; that Pliny, in his time, mentioned a combustible substance, which was thrown upon armed men, and burnt and destroyed them in the midst of the battle; that it was employed successfully by the successors of Constantine, and its composition was kept a state secret; that the Turks used it, or a composition of a similar nature, at the siege of Damieta, in 1249, forty-five years after the death of Roger Bacon; and, finally, that, when the composition and effects of gunpowder became known, the Greek fire, although it laid the foundation of the invention of gunpowder, was no longer in use, and the secret of the original preparation became lost. See [Gunpowder.]
Sec. XXXI. Of Mines and Mining.
A mine is a subterraneous passage, dug under the wall or rampart of a fortification, for the purpose of blowing it up by gunpowder; and mining is the art of accomplishing this effect.
The art of mining, having become one of the most essential parts of the attack and defence of places, should be well understood; and requires a perfect knowledge of heights, depths, breadths, and thicknesses; to judge perfectly of slopes and perpendiculars, whether they be such as are parallel to the horizon, or such as are visual; together with the true levels of all kinds of earth. To this may be added, a knowledge of rocks, clays, soil, &c. and the effect of gunpowder.
Mines were made long before the invention of gunpowder. The ancients made galleries, or underground passages, much in the same manner as the moderns, from without, under the walls of places, which they cut off from the foundation, and supported with strong props. The intervals were filled with all manner of combustibles, which, being set on fire, burnt their props, and the wall, being no longer supported, fell, by which a breach was made.