Up to the 1920s, although there was little need for a lighter, inventors descended upon the problems of fire making. Soldiers fighting in the War in Europe lived and died in trenches that were wet during rainy season. They wanted a reliable way to light a fire when needed. Matches were coated with wax to keep them waterproof, but wax covered matches did not light as easily as regular matches. Regular matches became useless in the trenches after the first rain. Lighters began to appear for use by the soldiers. These lighters had to be simple, light, and fool-proof. Most were not fool-proof, but a few were well made and easy to use. The old standard, flint and steel, was simple and with some engineering, practical for a portable lighter. The trick was making the flint part soft enough and the steel part hard enough to avoid rapid wearing out of the parts. By 1919, lighters using flint and steel were well established. Dunhill made a solid lighter. They found a ready market in the soldiers and demand for these lighter grew as other soldiers saw their benefits. After the war, the lighter’s use spread worldwide.