It stands unobtrusively in the Early Flight gallery on the ground floor of the National Air and Space Museum (NASM). Look below and just beyond the 1894 glider flown by aviation pioneer Otto Lilienthal, and there it is, a primitive radial aircraft engine not quite four feet in diameter, modestly displayed. But don't dismiss it. This small piece of machinery has a tale to tell.

By the start of the 20th century the Secretary of the Smithsonian, Samuel Pierpont Langley, had bet his reputation — not to mention tens of thousands of government dollars — that he would build the world's first powered, man-carrying flying machine.

Langley was no harebrained dreamer, but a serious scholar with a background in mathematics, architecture and astronomy. Coolly scientific, he demanded much of his staff. His memos often contained the words "I desire . . ." and his employees hopped to fulfill those desires.

Inspired by an 1886 lecture on the possibility of manned flight, he was badly bitten by the bug. By the 1890s he had built and tested a number of models, which were powered at first by rubber bands. He considered various engines — gasoline, carbonic acid gas, electric, even gunpowder — but at the time, such engines would have been too large, too dangerous or not powerful enough. Eventually, he settled on steam, and after a number of failed attempts, he built two gasoline-fueled, steam-powered models that flew beautifully. On two fine days in 1896 — one in May and one in Novembe — the little planes, each about 16 feet long, soared away from their launching pad, a houseboat on the Potomac River. Small steam engines whiffling happily, they held a steady course on an even keel, one covering 3,300 feet, the other reaching 4,200 feet and a speed of 30 miles an hour.

Langley had decided on a tandem wing configuration — two sets of wings of almost equal span set one behind the other — for what he called his "aerodromes." They had a large dihedral; that is, the wings formed a squashed V when seen head-on. This gave them stability in flight.

Professor Langley should have quit while he was ahead. But his success with small-scale powered flight intensified his dream of building an aerodrome big enough to carry a man. As his friend Octave Chanute — an important aeronautical guru of the day — pointed out, Langley had "cast iron ways." One was his conviction that simply reproducing those successful models on a grand scale would result in a man carrying "Great Aerodrome." This would require, among other things, a lot of horsepower in a lightweight engine, a daunting prospect a century ago.

As the Army and Navy geared up for the Spanish-American War in 1898, Secretary Langley's enthusiasm for flight stirred their interest. He wrote to a friend at Cornell that "an aerodrome capable of a speed of 30 miles an hour maintained for three hours, carrying an 'aeronaut' and possibly some missiles may be attempted." He added that he needed some sort of gas engine (there having been much progress in gasoline engines in the previous few years), and asked if his friend could recommend a "young man who is morally trustworthy ('a good fellow') with some gumption and a professional training."

In response, young Charles Matthews Manly showed up at the Smithsonian. A brilliant engineering student, he was about to graduate with a mechanical engineering degree from Cornell. When selected to meet Langley's request, he took off for Washington like a shot, receiving his degree in absentia.

One of Manly's first tasks was to supervise the construction of a remarkable gasoline engine designed by a Hungarian immigrant in New York, Stephen Marius Balzer. Balzer had been a watchmaker at Tiffany's, then studied engineering at night school while working at a machine shop. Such industry had paid off in 1894, when New Yorkers gaped at the city's first homegrown automobile — built by Balzer. Now in the Smithsonian's National Museum of American History, it's a simple structure of sturdy pipe work with a small three-cylinder engine to spin the rear axle.

Balzer's engine, light yet powerful, had intrigued Langley. He contracted with Balzer for the world's first "aero engine" to power what he hoped would be the world's first manned airplane, already being built in a shop behind the Smithsonian Castle where the Enid A. Haupt Garden now delights the eye.

Trying to meet Langley's "desires" for less weight and more power, Balzer put together in New York the five-cylinder engine now displayed, with Manly's modifications, at Air and Space. It was originally a rotary, like his automobile engine had been: the entire engine turned around the driveshaft. But Balzer had a terrible time getting it to work properly, or to generate adequate horsepower. Manly helped him, encouraged him, nudged him and strove to get him more money. Langley shelled it out, mostly from a $50,000 grant from Congress, and fidgeted while Balzer fussed.

Time dragged on. Month after month passed. Manly's notes to Langley indicate the growing frustrations of the team. July 1899: "I am rather at a loss to explain how it is that one day Mr. Balzer thinks the present cylinders will work, and the next day he thinks that the engine will have to be rebuilt. . . ."

September 1899: "The engine for the great aerodrome is as yet unfinished, but Mr. Balzer promises to be ready with it by the 22nd of the present month. . . ."

June 1900: "The gasoline engine which was contracted for on the 12th of December, 1898, by Mr. Balzer can neither be accepted nor condemned at the present moment."

In that same letter, dated June 19, Manly agreed to "go abroad for a few weeks" with Langley to investigate alternatives. In Europe, engineers advised them against the rotary design. Lubrication, for instance, was a problem, for a rotating engine obviously throws oil away from its center. As the cylinders spin around, oil gathers at their outer ends.

Why, then, had the idea of a rotary appealed to the Langley team at all?

For one thing, its spin cooled the cylinders. Air cooling meant that the tank, pipes and pump for water cooling weren't needed--an admirable loss of weight. Also, the spin of the engine served the function of a flywheel, a feature of some early engines that helped them to run more smoothly.

But as more time passed and more problems arose with Balzer's engine, Manly decided to follow the Europeans' advice. By the fall of 1900, he had given up on the rotary concept. In September, he wrote his boss, still in Europe, that his recent effort with the aero engine had "been with the cylinders held stationary and cooled by temporary water jackets." He had turned Balzer's rotary engine into a fixed radial — and one cooled by water instead of air.

At last problems began to fade and performance improve, with an immediate leap from 6-8 hp in Balzer's rotary to 12-16 hp in Manly's radial version. More tests and improvements followed. By March 1901 the radial engine was putting out some 18 hp, but Manly foresaw the need for more. So, with funds from new grants, he replaced Balzer's heavy pistons with light ones and increased the size of the cylinders. By March 1903, the rebuilt engine was spinning the aerodrome's two propellers at the rate of 575 revolutions per minute. "The engine proper," wrote Manly, "weighs 120 lbs., and develops on test 52 brake horsepower...." In this same letter to Langley, the young assistant writes that his confidence in the engine is so complete that "I am prepared to risk myself with it in actual flight."

He didn't have long to wait. In the summer of 1903, after test flights with a quarter-scale model, Langley was ready. By September, the Great Aerodrome roosted on its catapult atop a bulky houseboat in the Potomac. Last adjustments went on as though Langley, after 17 years of working toward this climax, and now 69 years old, could hardly bring himself to reach it.

On October 7, Manly climbed aboard, started the engine and ran it up to full speed. It had taken him and Balzer a total of five years for this impressive piece of machinery, with its five cylinders radiating star-like from its driveshaft, to be wrenched up to this zenith of its performance. Now, as its bellow reached full voice, he signaled for the plane's release.

"This was done," reads Manly's report, "and the car started down the track under the combined impetus of the launching springs and the propellers. . . ." And then: "I experienced a slight jerk and discovered immediately that the machine was plunging forward and downward. . . ."

Manly had no time to shut down the engine before hitting the water. He got dunked, but swam away unhurt. Much of the airplane's structure was crushed when it hit the water. So was Langley. The press howled with laughter. The much-touted flying machine had slipped into the water "like a handful of mortar."

The tragedy dragged on as Langley got his dream machine repaired and ready for another try. On December 8, 1903, Manly crawled back into the cockpit, revved up the engine, signaled . . . and again plunged into the Potomac. The wings had simply snapped in the rush of air. This time Manly nearly drowned in the icy river, and when he got back aboard the houseboat he cut loose with a blast of blue language in front of all the dignitaries who had been invited to witness the triumph. They were surprised. They shouldn't have been.

Just over one week later, the Wrights flew at Kitty Hawk and won the race for the air. Langley's mistake was in scaling up his small models without accounting for the fact that on the full-sized plane, drag would be increased exponentially. The Wrights started with full-sized gliders and had flown them for years. They knew how to fly. Manly had none of this experience — just guts.

But Langley's wreck had a wonderful engine — created for a plane that wouldn't fly. Had the craft flown, Manly's creation would have been the first airplane engine in the world; certainly, it was built earlier and far better than the 12 hp job that got the Wrights airborne. Balzer's original would have been the first aerial rotary, a type of engine that drove a swarm of fighter planes in World War I. They had all the same advantages of Balzer's, and the same problems — hard to control because of torque, hard to keep lubricated because of centrifugal force. Castor oil was the lubrication of choice for them, and many a pilot of an early German Fokker, British Sopwith or French Nieuport suffered digestive unrest by breathing the fumes flung back by a rotary.

The improvements made by Manly turned the engine into the world's first radial engine designed for flight, the same basic type of engine that took Lindbergh to Paris and drove many classic bombers and fighters in World War II.

Langley, shattered by defeat, died in 1906. Manly's health was marred by constant exposure to the intense heat of metalwork. He ran an engineering firm in New York, and died in 1927, only 51 years old. Balzer lived until 1940. Few remember his name.

But the heartbreaking efforts of this disparate team live on in their splendid little gray engine. Notice the sheen on those big cylinders. Could that be the shine of sweat? Or maybe the splash of tears?

Both seem likely.

By Edwards Park