It has been said that the first of the foregoing passages—“there are other natural wonders,” &c.—describes a rocket. As everybody knows, a rocket in its flight makes a whizzing noise and is followed by a trail of heated gas and sparks. The whizzing noise can only be compared to thunder by a total disregard of fact, for no sound resembles thunder less. Does thunder whizz? The fiery trail can only be called a flash by an equal disregard of fact: it gives a continuous light. But if the rocket carries a bursting charge which explodes in mid-air, the explosion may, with venial exaggeration, be said to produce a flash like lightning and a noise like thunder. Bacon was alluding to a bursting charge consisting of an explosive, and that explosive was gunpowder. Was Bacon aware of the projective force of gunpowder? There is nothing in his works (so far as I am acquainted with them) which suggests that he was. He knew that gunpowder exploded, and he believed that an army might be either actually blown up by it, or put to flight by the terror inspired by its explosion;[378] but he seems to have gone no further. He experimented, probably, with very small quantities of it; and the behaviour of gunpowder when fired in large quantities under pressure is so unlike its behaviour when fired in small quantities in the open air, that its projective force could neither have been predicted by abstract reasoning nor realised by even his powerful imagination. If a surmise be permissible, Bacon did not invent, he discovered gunpowder. Experimenting with some incendiary composition, prepared with pure instead of impure saltpetre, the mixture exploded unexpectedly and shattered all the chemical apparatus near it, thereby laying the foundation of the mediæval legend about the destruction of the Brazen Head. This suggestion, if correct, only adds one more item to the long list of accidental discoveries. The laws of the structure of crystals were discovered by Haüy’s accidentally letting fall a piece of calc-spar, which broke into fragments. Malus, chancing to look through a double refracting prism at the light of the setting sun, reflected from the windows of the Luxembourg Palace, discovered the polarisation of light. Galvani discovered galvanism by mere accident. The decomposition of water by voltaic electricity was accidentally discovered by Nicholson in 1801. However, whether as discoverer or inventor, Roger Bacon made and fired the first gunpowder. It fell to the lot of a persecuted English monk to fulfil the prophecy of Prometheus, that in the latter day there should appear “a wondrous being, who should call forth flashes brighter than lightning and sounds louder than thunder.”[379] PART II THE PROGRESS OF AMMUNITION CHAPTER IX ANALYTICAL TABLE OF AMMUNITION