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The Rail-Splitter’s invention for ‘Buoying Vessels Over Shoals’ is yet another indication of his homespun genius.

Throughout his presidency, it wasn’t unusual to see the tall, lanky figure of Abraham Lincoln down at the Washing- ton Navy Yard, examining and sometimes even testing new firearms. While that might seem odd, and an unexpected trait for the Great Emancipator, it was a reflection of Lincoln’s lifelong fascination with science and invention.

Lincoln submitted his own patent application for a device for “Buoying Vessels Over Shoals,” along with a model, to the U.S. Patent Office on March 10, 1849. He had to swear an oath to his invention’s originality before a Washington justice of the peace, and also paid a $30 fee. The patent for his invention was issued as number 6,469 on May 22, 1849. Lincoln had been inspired to design his creation after he witnessed a steamboat go aground on a sandbar during a trip on the Detroit River in 1848.

The president’s invention used inflatable air chambers—similar to giant bellows—attached on each side of a vessel with a system of sliding spars or shafts, ropes and pulleys to fill the chambers with air. The chambers could be inflated, either by steam power or manpower, to buoy a vessel over sandbars or other waterway obstructions. One big advantage to such a device was that a vessel’s cargo didn’t have to be offloaded before the buoyant chambers were inflated. In Lincoln’s vision, the bellows could be inflated simultaneously or individually, as the case might require, and easily folded up for storage in attached chambers when not in use.

After Lincoln’s election to the presidency, his unique stature as the only president to hold a patent did not go unnoticed. The December 1, 1860, issue of The Scientific American ran an illustrated article about Lincoln’s invention, describing it in detail. While the editors pointed out that the invention “illustrates forcibly the variety of talents possessed by men,” they also offered a none-too-subtle jab at its merits, stating, “We hope the author of it will have better success in presiding as Chief Magistrate over the people of the entire Union than he has had as an inventor in introducing his invention upon the western waters, for which it was specially designed.”

In April 1861, Harper’s Weekly also commented on Lincoln’s patent: “Among the registered patents in the Patent Office at Washington is one for buoying vessels through shallow waters, taken out some years ago by Abraham Lincoln, of Springfield, Illinois. The method is by the employment of air-chambers constructed on the principle of a bellows, and distended or contracted by ropes, as the depth of water may require….”

As president, Lincoln actively fostered invention. He was always eager and willing to hear about new ideas by inventors of his day. On March 3, 1863, he signed a bill creating the National Academy of Sciences.

Lincoln’s invention throws light on his mechanical aptitude as well as his way of thinking and analyzing, his penchant for expanding his learning and his interest in understanding disciplines other than politics, his fidelity to the political belief of internal improvements, his attempts at scholarly lecturing, and his admiration and fostering of invention and innovation as president. To understand Lincoln the inventor is to better understand Lincoln the man.


This article is adapted from Jason Emerson’s forthcoming book Lincoln the Inventor, scheduled for publication in January 2009 by Southern Illinois University Press.

Originally published in the February 2009 issue of Civil War Times. To subscribe, click here