Sleeping on a volcano The gunpowder magazines of Melbourne and their tramways

摘要

The explosive in common use when the first permanent settlers arrived in the Port Phillip district in 1834 was ordinary black gunpowder, all of it imported from England. Gunpowder consists of a mixture of one part of sulphur, one part of granulated charcoal, and six parts of saltpetre (potassium nitrate, KNO3). Known from antiquity in China, it was formally recorded by English chemist Roger Bacon in The Mirror of Alchemy in 1266. Gunpowder manufacture in bulk commenced in England in 1570, during the reign of Elizabeth I. It was commonly dispatched and transported in wooden casks held together with copper hoops. Such casks should be well made to both contain the powder and prevent the ingress of water, but many were not, either from the use of unseasoned wood or by poor workmanship. Gunpowder that leaked could be ignited quite easily by a simple spark or exposure to a flame.2