COSTON, Martha, American, b-1826. At the age of 21, and newly widowed, she found her ex-husband’s notebooks containing an idea for military naval signal flares. This was at the time of the American Civil War. His design did not work, but Martha saw ways of improvement. The flares were not bright enough and of too short a duration to be visible at a distance. They needed to be in various colours, so that colour combinations could have coded meanings. She sought help from chemists, who indicated that the relevant technology was that for fireworks. Martha then made fast progress and devised the red, green and white signalling systems that she patented in 1859 (pyrotechnic night signals). The US Navy took up the idea and used it in sea-battles and emergencies. In 1871 she patented improved versions with a twist ignition mechanism. Finally in 1876 she exhibited her maritime signal flares. From then on the flares were used by the US Navy, merchant ships, and yachts as a requirement of maritime insurers.