While searching for ‘historical women in science,’ (endearing subjects, both), I came across the story of Martha Jane Coston. Born Martha Hunt in Baltimore, MD on December 12, 1826, she invented the Coston flare, a device for signaling at sea, used extensively by the Union during the Civil War.
When she was quite young, during the 1830's, Martha's family relocated to Philadelphia. She met and eloped with a promising young inventor, named Benjamin Franklin Coston while just 16 years old. At the time of their marriage, Ben, just 21, would later become the director of the U.S. Navy’s scientific laboratory in Washington, D.C. During his time at the Navy Yard, he developed a signaling rocket and percussion primer for cannons. Ben also tested color-coded night signals that helped with ship-to-ship communication. Visual signals during this time were relegated to flags during daylight hours and lanterns at night. When a financial dispute over payment for his work on the percussion primer erupted in 1847, Ben resigned his commission with the Navy and became president of the Boston Gas Company. Just 18 years earlier, the first public gas lamp was lit in Dock Square, adjacent to Faneuil Hall.
Ben’s work with chemical fumes, both at the Navy Yard, and with the BGC, caused his health to deteriorate, and he died a year later as a result of chemical exposure. He was just 28 years old. His plans on signal flares and their chemical formulas were tucked away among a stack of personal papers. Tragedy followed Martha after her husband’s death. She lost her mother and two of her four children within two years. Desolate, both financially and emotionally, Martha was determined to support her family. While searching through her husband’s papers, she came upon his night signaling notes from his time at the Navy Yard. Although promising, his calculations needed substantial work before they could be shaped into a usable signaling system.
Martha dedicated herself to her late husband's theories, committed to seeing them into practicable application. She toiled for nearly ten years to develop a flare signaling system based on her husband’s early work.
With scant knowledge of both pyrotechnics and chemistry, Martha relied on hired chemists and fireworks experts, with varied results. While watching a fireworks display in New York City celebrating the transatlantic telegraph cable, she realized her system needed a bright blue flare, in addition to the red and white flare she had already developed. Martha established the Coston Manufacturing Company in 1858, along with a pyrotechnics expert to supply the blue flare color, to create signal flares.
A quote from her early struggles:
"It would consume too much space, and weary my readers, for me to go into all the particulars of my efforts to perfect my husband’s idea. The men I employed and dismissed, the experiments I made myself, the frauds that were practiced upon me, almost disheartened me; but despair I would not, and eagerly I treasured up each little step that was made in the right direction, the hints of naval officers, and the opinions of the different boards that gave the signals a trial." – Martha J. Coston, A Signal Success. The Life and Travels of Mrs. Martha J. Coston (Philadelphia, PA: Lippincott Company, 1886)
On April 5, 1859, Martha was granted U.S. Patent number 23,536 for a pyrotechnic night signal and code system. The patent listed her as ‘administratrix,’ for her deceased husband, who was named as an inventor, even though the bulk of the work was done by Martha. Utilizing a combination of colors, the Coston flares enabled ships to signal to one another, and send signals to shore. Captain C.S. McCauley of the U.S. Navy recommended the use of her flares to Secretary of the Navy, Isaac Toucey, in 1859. After extensive testing, which demonstrated the effectiveness of the system, the U.S. Navy placed an initial order of 300 flares and later followed up with an order for $6000 worth of the flares. In today’s 2019 dollars, this amount had the equivalent purchasing power of $184,733.49.
Martha obtained patents in England, Italy, France, Sweden, Denmark, and the Netherlands. She traveled to England, and then to Europe, marketing her invention. Returning to the U.S. in 1861 on the brink of the Civil War, she immediately went to Washington to petition Congress to purchase her patent so that the flares could be used to aid the Union cause. Legislators passed an act on August 5th authorizing the U.S. Navy to purchase Martha’s patent for $20,000, half of what she originally requested.
Coston flares were widely used by the Navy during the conflict, proving effective in capturing Confederate blockade runners during the Union barricade of southern ports. They were also instrumental in coordinating naval operations during the Battle of Fort Fisher in North Carolina, from January 13-15, 1865, once called Southern Gibraltar because of its strength. Fort Fisher protected the vital trading routes of the port at Wilmington, NC.
Writing her autobiography years later, Coston received a letter from Admiral David D. Porter, commanding officer of the Fort Fisher attack, detailing the role the Coston Signal played in the battle. In the concluding paragraph of his letter, he wrote:
I shall never forget the beautiful sight presented at ten o’clock at night when Fort Fisher fell. I was determined to be a little extravagant on that occasion, and telegraphed by the signals to all creation that the great fort had fallen and the last entrance to the Southern coast was closed. The order was given to send up rockets without stint and to burn the Coston Signals at all the yard-arms, mast-heads, along the bulwarks, and wherever on shipboard a light could show. The sea and shore were illuminated with a splendor seldom equalled [sic]. . . What could there be more beautiful than the Coston signals on that occasion, and what more could I say of them?
Yours truly and respectfully, David D. Porter Admiral, U.S. Navy
On June 13,1871, six years after the war ended, Martha obtained a patent in her own name, Patent No. 115,935, for ‘Improvement in Pyrotechnic Night Signals.’ Her company had supplied flares to the Navy at less than cost, due to inflation, and she now sought $120,000 in compensation. Martha pursued her claim for ten years but was only offered $15,000. If her husband had still been alive, would she have been given more?
Every station in the U.S. Life-Saving Service (a government agency begun in 1848 to save the lives of shipwrecked mariners and passengers, and forerunner to the U.S. Coast Guard) was equipped with Coston flares, saving countless people. The Coston signal flare and code system was also used by the U.S. Weather Service, military institutions across Europe and South America, commercial merchant vessels and private yachting clubs.
Martha passed away on July 9, 1904, but her company, later called Coston Signal Company and the Coston Supply Company, remained in business until the late twentieth century.
In 2006, she was posthumously inducted into the National Inventors Hall of Fame.