Here’s what you’ll learn when you read this story:

• American obstetrician Martin Couney saved thousands of babies in the early 20^th century thanks to his neonatal sideshow featuring baby incubators.
• Because New York City lacked neonatal care at the time, many mothers rushed to Couney’s exhibit for help, which he provided free of charge.
• In 1939, toward the end of his career, Couney estimated that 8,000 babies had been in his care over his four decades-long career, and 6,500 survived.

Today, the baby incubator is a mainstay of any Neonatal Intensive Care Unit (NICU). A climate-controlled container enclosed by transparent acrylic or polycarbonate, these sterilized artificial wombs regulate temperature, humidity, and oxygen levels while protecting premature infants (or preemies) from life-threatening viral infections. These amazing inventions have no doubt saved countless lives, but before they became the life-saving machines of today, they were a sideshow attraction.

Following the Franco-Prussian War in the early 1870s, Europe was at a low point for population growth. One method for raising birthrates was, of course, to have more babies, but another was to drastically lower the infant mortality rate—and that gave French obstetrician Stéphane Étienne Tarnier an idea. What if doctors used warming chambers (which were initially designed for poultry) for premature infants to aid in thermoregulation? Tarnier’s creation was first introduced in L’Hôpital Paris Maternité in 1880, and his assistant, Pierre Budin, published results of their success in the following years. Unfortunately, many doctors saw the invention as pseudo-scientific—the medical world needed to be sold on the idea.

Enter: American obstetrician Martin Couney. An apprentice of Budin’s (though there is no evidence he ever held a medical degree), Couney similarly believed in the incubators’ promise. But instead of shopping the invention to different hospitals or medical universities, Couney took a decidedly different approach. He developed what became known as the Kinderbrutanstalt, or “child hatchery,” at the World Exposition in Berlin in 1896, having somehow convinced the nearby Berlin Charity Hospital to borrow premature babies for the exhibition, according to Columbia University

Eventually, in 1898, Couney brought this remarkable invention to the United States, and specifically set up the display as a sideshow spectacle at Luna Park in Coney Island, New York, in 1903. At the time, the city had no neonatal facilities, so mothers regularly rushed their newborns to Couney’s exhibit, which was approved by the New York Health Department. Because he charged visitors to see the “Living Babies in Incubators,” according to the large signs adorning the exhibit, Couney provided this necessary neonatal care free of charge, and hired a cadre of nurses to look after the babies.

Demand was so high that Couney eventually opened another exhibit at a nearby amusement park called Dreamland. When that amusement park burned down on May 27, 1911, Couney rushed the babies to Luna Park and saved them all—even though some had to double up in the incubators.

During the Chicago World’s Fair in 1933, Couney’s work finally reached center stage. During the first year of the exhibit, Couney saved 58 babies with his incubators, and on July 25, 1934, he organized a “homecoming” for all of the babies he cared for the previous year, along with their mothers. Some 41 babies returned, according to Smithsonian.

In a 1939 New Yorker profile titled “Patron of the Preemies,” Couney said that some 8,000 babies had been in his care since 1896, and estimated that 6,500 of them survived—a success rate of 85 percent. When the New Yorker asked him about the city’s plans to centralize its neonatal care at Cornell Medical Center, he said that when they did so, he’d retire and travel South America.

“All my life I have been making propaganda for the proper care of preemies, who in other times were allowed to die,” Couney said. “I get letters every year from people who their parents told them they were raised in my incubators.”