Razor be used on both sides, with two open edges. The blade on the double-edged safety razor is slightly curved to allow for a smoother and cleaner shave. In 1901, the American inventor King Camp Gillette, with the assistance of William Nickerson, patented a new variation of safety razor with disposable blades. Gillette realized that a profit could be made by selling an inexpensive razor with disposable blades. This has been called the razor and blades business model, and has become a very common practice for a wide variety of products. Many other brands of safety razors have come and gone.
Peters Cartridge Company on 15 July 1890 triggered an explosion killing twelve people and starting fires destroying the railroad station, the freight house, two Peters Cartridge Company office buildings, the shell factory, the cartridge loading plant, a large warehouse and six employee residences. Wood-frame structures were rebuilt on the opposite side of the river from the old powder works included a large shot tower completed in 1895. The last wood-frame structures were machine shop building R-3 and shotgun shell loading building R-21 built in 1907. With the approach of World War I the company received large ammunition orders from the Russian Empire and