transport applications. Since they can be used only once, fusees nowadays are usually intended for emergency use (as opposed to the lanterns typically used during normal operating conditions). However, in the days before train radio communications, fusees were used to keep trains apart in dark territory. A railroad fusee was timed to burn for 10 minutes, and quantities were dropped behind a train to ensure a safe spacing. If a following train encountered a burning fusee, it was not to pass until the fusee burned out. Fusees made specifically for railroad use can be distinguished from highway fusees by a sharp steel spike at one end, used to embed the fusee upright in a wooden railroad tie. In forestry and firefighting, fusees are sometimes used in wildfire suppression and in the ignition of controlled burns. They ignite at and burn as hot as . They are especially effective in igniting burnouts or backburns in very dry conditions, but not so effective when fuel conditions are moist. Since controlled burns are often done during relatively high humidity levels (on the grounds that they could not be safely contained during periods of very low humidity), the driptorch is more effective and more often used. Fusees are also commonly carried by wildland firefighters for emergency use, to ignite an escape fire in surrounding fuels in case of being overrun by a fire if no other escape routes are available. Calcium phosphide is often used in naval flares, as in contact with water it liberates phosphine which self ignites in contact with air; it is often used together with calcium carbide which releases acetylene. Law enforcement also may use flares (either propped on a biped or laid flat) to signal traffic hazards or that a road is blocked, often as a more visible replacement for traffic cones. Law enforcement in the United States usually use magnesium-based flares that last from 15–30 minutes. Military use Maritime signal flare In 1859, Martha Coston patented the Coston flare based on early work by her deceased husband Benjamin Franklin Coston. It was used extensively by the US Navy during the Civil War and by the United States Life-Saving Service (the precursor to the US Coast Guard) to signal to other ships and to shore. Illumination In 1922, a "landing flare" was an aerial candle attached to a parachute and used for landing an airplane in the dark. The