Etienne Bottineau (born on this day in 1738 in Champtoceaux, France) was a career-seaman -- first in the merchant marine, then briefly in the service of Louis XV's Royal Navy. Passing his time shipboard by making observations of navigation techniques, he began to develop a question which became the catalyst for his mysterious life's work: shouldn't a vessel approaching land produce a visible effect on the atmosphere which could be seen by the practiced eye and used to predict the arrival of a ship before it would be visible on the horizon?
His shipmates all thought the question itself was far-fetched and that Bottineau was nuts, but he left the Navy to stay in Mauritius (then I'le de France) and to work on his crazy hypothesis. With a clear sky and few vessels coming to visit (making for fewer possibilities for error), in 6 months Bottineau succeeded in developing a technique for "seeing beyond the horizon" -- watching the atmosphere on the horizon and predicting the arrival of ships three days before they could become visible on the horizon.
At first, he used his new technique, which he called nauscopy, to win bets around the docks. Between 1778 and 1782 he correctly predicted the arrival of 575 ships to Mauritius, many as much as 4 days before they could be sighted, and the local government took notice. In 1782, the governor of Mauritius began to record Bottineau's predictions, and at the end of 2 years, Bottineau had such an outlandish record of accuracy (from land and at sea) that the local French government offered Bottineau a lump sum of 10,000 livres and an annual pension of 1,200 livres if he would reveal his secret to the government. He declined the offer; he was convinced that he had made an important scientific discovery, and instead he wanted to go to France to bestow this gift on the nation of his birth and be the great teacher of the new science of nauscopy.
In Paris, however, Bottineau's offers met with indifference in the royal bureaucracy of Louis XVI, and opinion-leader Abbe Fontenay, the editor of the Mercure de France, sneered at Bottineau's offer without studying it. Humiliated and disgusted, Bottineau disappeared without revealing his secret technique. A Scottish journal reported his death in Pondicherry, India just before the French Revolution (1789), and Jean-Paul Marat, the occasional scientist himself, considered Bottineau notable enough to mention his death in a letter to a friend.
Several people later claimed to have mastered nauscopy, but Bottineau's technique has never been documented. The invention of practical radar by Robert Watson-Watt in 1935 no doubt rendered Bottineau's science of nauscopy a mysterious irreproducible result of the quaint and distant nautical past, or perhaps a good seacoast sun-parlor trick.