Cowen’s inventions, in fact, often developed in ways he hadn’t intended. He meant to revolutionize photography in 1898 with his fuse for igniting magnesium-powder flashes, but instead the U.S. Navy bought 24,000 to use in detonating underwater mines. Then he designed little metal tubes to illuminate flowers in their pots, which another man used to start the Eveready flashlight company.

And shortly after that Cowen created small electric train cars that traveled on a circular track, thinking they’d make an eye-catching display in shop windows. The railroad cars of the Lionel Lines weren’t very effective as advertising though; people asked to buy the trains themselves instead. Lionel trains most often ended up in people’s homes, underneath the Christmas tree. (He wasn’t the very first American manufacturer of electric model trains. Carlisle & Finch of Cincinnati, Ohio, had been making them since 1896.)

Born in 1877 as Joshua Lionel Cohen, Cowen grew up in New York City, first on the Lower East Side and then at 104th Street and Madison Avenue. Cowen’s unorthodox childhood is nicely described in the Dictionary of American Biography : “Repelled by the efforts of teachers to guide him in uninteresting directions, he began experimenting at home with various explosive mixtures.”

One unsuccessful invention was an early dry-cell battery, with only a thirty-day life. But Cowen’s success in 1898 with the Navy’s detonators gave him a $12,000 stake, which he used to develop several battery-powered devices, including the flowerpot lights. A businessman named Conrad Hubert liked the idea so much that he became Cowen’s traveling salesman.

One day Cowen, bored with the novelty flowerpots, gave Hubert the company. Hubert decided that people needed flashlights, not little flower lights, and after improving the design, he started the American Eveready Company, which earned him almost six million dollars in two decades.

Cowen turned his attention to even smaller electrical devices. He invented a battery-operated fan, but when the weather turned cool, he was left with a motor and nowhere to put it. One afternoon, according to company legend, he called to his assistant, “I’ve got it! We’ll make a little train!”

The earliest Lionel train was a flatcar with a motor and battery, which ran on a handmade circular brass track. For the next fifty years, Cowen kept innovating, ruling the toy-train world as he introduced the transformer and three-rail track (1906), locomotives (1907), the sequence switch (1926), which allowed remote-control operation of trains and track switches, and the steam whistle (1935).

Almost all Lionel Lines models were replicas of full-size locomotives or cars operating somewhere on a real American railroad, and the company received blueprints from railroad companies whenever new stock was introduced. Cowen was notorious for his commitment to accuracy; in one famous incident he was upset to discover that a New York Central engine had 1,402 rivets, while his Lionel model had only 1,399. The inventor never liked what he called the “inartistic” designs of his competitors’ Ives trains, and after he bought the rival and dissolved it in 1933, he threw its model-making dies into the Connecticut River.

The company was consistently successful, except for one difficult period during the Depression that it survived thanks to Walt Disney: toy-train sales were down, but a one-dollar wind-up handcar operated by Mickey and Minnie Mouse sold a quarter of a million units. By 1953, when Cowen was getting ready to retire, Lionel employed more than 2,500 people and controlled two-thirds of the American model-train market. Some 25,000 miles of Lionel Lines track had been laid in sixty-three countries, far more than for any single railway.

The company began to lose money soon after, and by 1969 it was sold to a conglomerate, General Mills. In 1986 Richard Kughn, a Detroit real estate developer and modelrailroad buff, bought Lionel and formed Lionel Trains, Inc., continuing the tradition that Cowen began by leading and sparking innovation in the model-train market.