Christian Lambertsen

It was summer 1940 in Cleveland, Ohio. Christian Lambertsen was wearing a breathing mask and standing beside a canary and dog inside an airtight chamber. With the local press and fire department in attendance, the medical student was to demonstrate his own invention: a Lambertsen amphibious respiratory unit (LARU), an early version of scuba gear (self contained underwater breathing apparatus).

Lambertsen already had successfully shown its underwater capabilities. Now he would show that it could protect against a hazardous atmosphere. Oxygen was removed from the chamber and replaced with cyclopropane, a flammable anaesthetic gas, according to Richard D Vann, a diving historian and professor emeritus in anaesthesia at Duke University school of medicine in Durham, North Carolina. The canary, as expected, fell unconscious from its perch, then the dog, then, unexpectedly, Lambertsen. Firefighters broke into the chamber to rescue the unconscious inventor. The problem, Professor Vann said, was that cyclopropane had penetrated the latex breathing bags.