IN THE EARLY 1930S A TALL, THIN CANADIAN-BORN Chicagoan named Harry J. McCollum invented a car heater that burned raw gasoline. Two things made it amazing. First, it didn’t blow up. Second, it made the interior of his old Chrysler toasty warm in just ninety seconds.

McCollum took a direct approach to marketing his product. One blustery winter day in 1934, he pulled up to the Stewart-Warner plant on Chicago’s Diversey Parkway and talked the guard into letting him see Arden LeFevre, the company’s chief engineer. McCollum explained how the heater worked; LeFevre called his staff over, and they discussed it for several hours. Finally McCollum suggested they go out to his car and see the heater in action.

“It was one of those cold, raw days such as only Chicago can come up with,” a later Stewart-Warner employee recalls being told by McCoIlum. “The car was thoroughly chilled when they got into it, but the heater worked like a dream, and within seconds plenty of heat was pouring out, making it quite comfortable in a couple of minutes. The demonstration … resulted in a contract.” Or, as McCollum wrote in his shop diary that evening: “Today I demonstrated the heater to Stewart-Warner. It worked better than it ever had before and probably better than it ever will again.”

Here’s how it worked: Gasoline drawn from the carburetor float bowl by engine vacuum was piped through a thin copper tube into a firing chamber, where it was atomized and ignited by a glow plug. The resulting horizontal flame could be adjusted with a knob that controlled the fuel orifice. The flame warmed a finned oven section inside the heater, and an electric fan blew air over the oven and into the car. Combustion gases were drawn back into the engine intake manifold, again by vacuum. Thermostats made sure that the glow plug turned off after ignition and that the fan didn’t come on too soon.

In the 1930s, as now, most car heaters worked by circulating water from the engine’s cooling system. In cold weather you often had to run the engine for ten or fifteen minutes before the passenger compartment warmed up. The South Wind heater (as Stewart-Warner called it) cost a little more to buy and operate, but even on the chilliest mornings you would be warm in ninety seconds. It was like driving with a fireplace in your car; in fact, if you didn’t turn down the flame, you’d roast.

Stewart-Warner built two hundred South Wind heaters in 1935 but had to recall them because the glow plugs sometimes didn’t light and the flame tended to scorch the fan. An improved version arrived in 1936; by 1948 more than three million had been sold, and daily production was more than forty-five hundred units. The heaters fitted beneath the dashboard, where drivers could kick them on and off with their feet. Ads of that era showed young women sitting in South Wind-equipped cars saying, “C’mon in here … get warm with me.”

During World War II large South Wind heaters kept military fliers warm; they were also installed in many ground vehicles. In the Korean War they warmed everything from tanks to jeeps to light planes. They saw civilian duty in school buses, motor homes, and ambulances and as preheaters for large diesel engines. You could buy them for Volkswagen Beetles well into the 1970s. South Winds are still being made for military applications and as diesel preheaters, but not for automobiles, where they have been superseded by improved systems using engine heat.

Harry McCollum remained an unsalaried inventor for Stewart-Warner and came into the labs every day for years. Royalties on the South Wind made him wealthy, but he continued to live and dress modestly and drive an old car. On one of his rare vacations, McCollum and his father found themselves in Miami, where Harry got an idea for a new type of fuel pump. The two men went to a Sears store, bought a lathe, a drill press, and some other tools, and set up shop in their hotel room. This hasty prototype worked, so Harry and his father cut their vacation short, hurried back to Chicago, and finished developing it.

In 1944 McCollum found out he had a heart condition. He was developing an artificial heart when he died suddenly later that year.