Casimir Zeglen was truly a man of the cloth. He was a Catholic priest — with an obsession for silk underwear — but the pleasure he got from silk touching skin was because it stopped bullets.
The vests worn today by soldiers, police officers and marked men are made with lightweight armor and sophisticated, bullet-resistant fibers like Kevlar that evolved as weapons got more powerful. Yet they work much the same way as Zeglen’s silk invention: The material catches and deforms slugs, then spreads the force of the strike over a larger area of the vest.
Today, statistics about military and law enforcement use of vests and body armor reveal the kind of effectiveness Zeglen dreamed off. FBI statistics show annual declines in police officer deaths, with researchers attributing the drop to increased use of body armor. In a 2006 Pentagon study, researchers found 80 percent of Marines killed between 2003 and 2005 from upper-body injuries could have survived had they been wearing better body armor.
Zeglen is an unlikely figure in the history of preventing such violent deaths. Born a peasant in the Ukraine, he entered a monastery there at 18. Fearing he would be forced to serve in the Austrian army, he asked to be sent away to serve a church. He eventually landed at a Polish church in Chicago in 1890.
By Zeglen’s own account, the assassination of Chicago Mayor Carter Harrison made him realize he wanted to “create a product of great usefulness to the world.” He began experimenting with a cloth made from moss, hair and steel shavings.
He turned to silk when he read an 1887 article by a physician who described a man who was shot but saved by a silk handkerchief in his breast pocket. The doctor, George Goodfellow, conducted his own experiments with silk that was as thick as 18 to 30 layers.
Like Jony Ive searching for the perfect gold alloy for the Apple Watch Edition, this bulletproof vest pioneer chose silk because of special physical properties, like greater flexibility and a higher breaking point than most textiles.
Testing the bulletproof vests
Presumably, Zeglen’s experiments included firing guns at his creations. He settled on a silk fabric he discovered at mills in Austria and Germany in 1895, combining it with a chemical he never disclosed to keep other inventors from stealing his ideas.
Zeglen continued to perfect his vest: He filed a patent in 1897 for a vest that was coated with a woven linen cloth, Angora wool and layers of stacked silk threads. This alone could stop bullets from the low-caliber pistols of the time. He filed a second patent for a steel sheet insert that would be effective even against modern rifles.
Zeglen took on a business partner, Jan Sczepanik, and the two began conducting public tests for military officials, police, doctors and journalists.
“A fabric produced, which is one-eighth of an inch in thickness, four-ply, presents this perfection of weave, and all efforts to penetrate it with bullets have proved futile,” reported the Brooklyn Eagle in a 1902 story that previewed an upcoming public demonstration of Zeglen’s invention.
One of the best resources detailing the rise of Zeglen’s invention is a recent article from Arms & Armour by Slawomir Lotysz, a professor of history of technology at Police Academy of Sciences in Warsaw.
At first, the tests were done against wood and Zeglen’s material successfully withstood shots from a variety of distances, Lotysz wrote. In one test, doctors from a local dental college strapped a female corpse to a wall and wrapped the torso in Zeglen’s fabric.
None of the 30 shots fired from a cold revolver from 3 meters to 15 meters away penetrated the material. However, the cadaver had two fractured ribs. The next test was on a live Great Dane and, again, the material did its job.
Human volunteers offered to test Zeglen’s invention for cash, and the inventor even served as his own guinea pig in 1897, again before an audience of doctors from the dental college. Zeglen took shots from various caliber revolvers, saying after one shot that “the concussion hurt no more than if someone had given me a light poke with a cane.”