Martha Coston

Martha Coston invented a system of pyrotechnic signal flares that not only gave the U.S. Navy a great advantage in communication during the Civil War, but also advanced boating safety worldwide.

Coston was born Martha Hunt in Baltimore in 1826. When she was 16, she eloped with Benjamin Franklin Coston, an inventor who had worked as a naval scientist at the Washington Navy Yard. However, not long after they married, Benjamin’s health began to decline due to chemical exposure at work, and he passed away in 1848.

Following the death of her husband, Coston also tragically lost two of her children and her mother. With a lack of familial support, she began to fall into poverty, and she needed to find a way to support herself and her remaining children.

Coston began looking through her husband’s papers, seeking work she could potentially sell. She came across a set of notes that provided an outline for a signaling system using color-coded flares. Though her husband’s notes did not include any details, Coston was determined to make the signaling system a reality. She challenged herself to create a complete, practical system based on this initial design idea.

For more than 10 years, Coston worked tirelessly to teach herself about pyrotechnics and chemistry, how to start and conduct her own company, how to work with government agencies, and most importantly, how to protect her intellectual property.

While working on her signal system, Coston found inspiration in 1858 while watching a fireworks show in celebration of the first transatlantic cable in New York City. With this colorful display in mind, she aimed to develop a patriotic trio of flares that would burn red, white and blue. Though she was successful in developing red and white flares, blue flares proved especially challenging to create.

In an effort to learn how she might develop blue flares, Coston wrote to New York pyrotechnics companies under a man’s name so she would not be ignored. However, Coston eventually settled on developing bright green flares instead. Once her red, white and green options were each complete, a patent for her night flares was issued in 1859. Coston was named as administrator of the patent, and her late husband was named the inventor.

Having founded the Coston Manufacturing Co., Coston began trying to sell her signal flares. The flares were bright and long lasting, and they could be used in coded combinations of colors. They would provide great advantages for both ship-to-ship and ship-to-land signaling over great distances. The U.S. Navy showed interest in the signal flares but delayed making a purchase until after the start of the Civil War. Throughout the war, the Coston Manufacturing Co. sold the signals to the U.S. Navy at cost.

According to Coston’s autobiography, Navy tests concluded, “[T]he importance of being able to communicate between distant points at night under almost any circumstances can hardly be estimated, and in the Coston signal, I think, you will find all that can be desired.”

The Coston signal flare became standard safety equipment for all watercraft and was adopted worldwide, enabling the great success of Coston’s business until the late 20th century. Coston’s products were used by the U.S. Life Saving Service (the forerunner of the U.S. Coast Guard), the U.S. Weather Service, military institutions in England, France, Holland, Italy, Austria, Denmark and Brazil, private yacht clubs and commercial merchant vessels.