Whichever of the two views may be correct it is certain that a knowledge of gunpowder was possessed by the great alchemist, Roger Bacon, who in A.D. 1249 committed to paper an account of its properties.[39] To Berthold the Black Friar is given the credit for its application to military ends; whom legend, in an impish mood, has hoisted with his own discovery. In a learned work on the early days of artillery an English writer has described the difficulties encountered in tracing the first stages of the evolution of guns and gunpowder. Confusion was caused by the fact that, after gunpowder had been introduced, military engines were still known by the same generic names as those borne in pre-gunpowder days. No contemporary pictures of guns could be discovered. The loose statements of historians, the license of poets, and the anachronisms of the illuminators of the medieval MSS., all tended to lead the investigator astray and to make his task more difficult. The statements of the historians are indeed whole hemispheres and centuries apart; as for poets, our own Milton assigned the invention of artillery to the devil himself; and “from the illuminators we should gain such information as, that Gideon used field pieces on wheeled carriages with shafts, when he fought against the Midianites, as in a MS. in the British Museum.”[40] Of all the clues which throw light on the origin of artillery the most important yet discovered lies in some MSS. belonging to the city of Ghent. After a list of municipal officers for the year 1313 occurs the entry: “Item, in this year the use of bussen was first discovered in Germany by a monk.” And there is evidence that in the following year “guns” were manufactured in Ghent and exported to England.[41] The same century was to witness a wonderful development of the new-found power. It was but natural that the first application of gunpowder to warlike purposes should have been, not only to strike terror by violent explosion and thus obtain an important moral effect, but to project the missiles already in military use: arrows and ponderous stones. Two distinct types of artillery were thus foreshadowed. The first took the form of a dart-throwing pot or vase, a narrow-necked vessel from which, in imitation of the cross-bow, stout metal-winged arrows were fired; while, for projecting stones of great size and weight in imitation of the ancient siege-machines, large clumsy pieces made of several strips of iron fitted together lengthways and then hooped with iron rings were eventually developed.