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
William Samuel Henson which is at right angles with the handle, and resembles somewhat the form of a common hoe." While a major improvement on the previous form of safety razor, an additional improvement was needed to make safety razors common. In 1901, Gillette combined Henson's T-shaped safety razor with disposable blades, and produced the modern razor. Henson published a pamphlet on astronomy in 1871 suggesting that the solar system formed from cold dust and gas, and discussed how it could condense into meteors and comets, and further condense into planets, moons and the sun, in the process heating up. He also discusses