Many designs were jointly examined by the army and navy, but were unsatisfactory, probably because of the safety and arming features. However, in 1846 the design by Quartermaster Freeburn of the Royal Artillery was adopted by the army. It was a wooden fuze some 6 inches long and used shear wire to hold blocks between the fuze magazine and a burning match. The match was ignited by propellant flash and the shear wire broke on impact. A British naval percussion fuze made of metal did not appear until 1861. Gunpowder was used as the only form of explosive up until the end of the 19th century. Guns using black powder ammunition would have their view obscured by a huge cloud of smoke and concealed shooters were given away by a cloud of smoke over the firing position. Guncotton, a nitrocellulose-based material, was discovered by Swiss chemist Christian Friedrich Schönbein in 1846. He promoted its use as a blasting explosive and sold manufacturing rights to the Austrian Empire. Guncotton was more powerful than gunpowder, but at the same time was somewhat more unstable. John Taylor obtained an English patent for guncotton; and John Hall & Sons began manufacture in Faversham. British interest waned after an explosion destroyed the Faversham factory in 1847. Austrian Baron Wilhelm Lenk von Wolfsberg built two guncotton plants producing artillery propellant, but it was dangerous under field conditions, and guns that could fire thousands of rounds using gunpowder would reach their service life after only a few hundred shots with the more powerful guncotton. Small arms could not withstand the pressures generated by guncotton. After one of the Austrian factories blew up in 1862, Thomas Prentice & Company began manufacturing guncotton in Stowmarket in 1863; and British War Office chemist Sir Frederick Abel began thorough research at Waltham Abbey Royal Gunpowder Mills leading to a manufacturing process that eliminated the impurities in nitrocellulose making it safer to produce and a stable product safer to handle. Abel patented this process in 1865, when the second Austrian guncotton factory exploded. After the Stowmarket factory exploded in 1871, Waltham Abbey began production of guncotton for torpedo and mine warheads. In 1884, Paul Vieille invented a smokeless powder called Poudre B (short for "poudre blanche"—white powder, as distinguished from black powder) made from 68.2% insoluble nitrocellulose, 29.8% soluble nitrocellusose gelatinized with ether and 2% paraffin.