Razor razors were the most common form of shaving before the 20th century and remained common in many countries until the 1950s. Barbers were specially trained to give customers a thorough and quick shave, and a collection of straight razors ready for use was a common sight in most barbershops. Barbers still have them, but they use them less often. Straight razors eventually fell out of fashion. Their first challenger was manufactured by King C. Gillette: a double-edged safety razor with replaceable blades. Gillette's idea was the use of the "loss leader" concept, in which the razors were sold at a
Safety fuse Safety fuse The safety fuse is a type of fuse invented and patented by English inventor William Bickford in 1831. Originally it consisted of a "tube" of gunpowder surrounded by a waterproofed varnished jute "rope". It replaced earlier and less reliable methods of igniting gunpowder blasting charges which had caused many injuries and deaths in the mining industry. The safety fuse burns at a rate of typically about 30 seconds per foot (1 second per cm). Documented evidence suggests that the earliest fuses were first used by the Chinese between the 10th and 12th centuries. After the Chinese had invented