A Little Green Flash 2/6/2019 whwsailboat 89 views On top of a cement tower on the French island of Marie Galante, Guadeloupe, West Indies, sits a light that, for sailors, marks the town of St. Louis. It is a diminutive structure. It is not a great noble lighthouse that captures the imagination, or love, that so many people hold for these structures. It is not a famous Eddystone perched on a wave swept rock outcropping in the North Sea nor the tall diamond painted Hatteras light that marks the grave of countless hulls swept up on Diamond Shoal. It is not even the Little Red Lighthouse under the George Washington Bridge in New York City, made famous in a children's book. Other than listed in the Official List of Lights catalogue, I doubt it shows up in any coffee table publication.It is a modest cement tower perched alongside a nondescript building on the Rue Deguse on the water's edge. The top is painted green with S. Louis in black letters to inform sailors the name of the town. The town dock, where the ferries from Guadeloupe land, is just to the south. No plaque immortalizing its place in history, no mention of its existence.All these navigation lights, either in tall "houses" on sandy beaches, atop screw pilings in a bay or key, nestled under a bridge in a major city, on rock cliffs or atop buildings in town, virtually all, share something in common. Yes, of course, they share the same purpose: an important landmark for navigators. Oddly, that purpose is becoming less important as the lore and love of lighthouses grow while other navigation aids dominate. Lighthouses existed since ancient fires marked locations to enable sailors to determine their location. Then came RDF, radar, Decca, Loran, GPS, AIS marks and Google Earth! The need to know where you are never ceases.Arguably, lighthouses owe their place in history, or at least their usefulness, to the French civil engineer: Augustin Fresnel. Theresa Levitt wrote a wonderful account of Fresnel and his "lens" that made lighthouses "stand out" in the darkness of night. Her book "A Short Bright Flash" is an interesting read and am grateful to my brother Ron to recommending and giving me the book.The Fresnel Fresnel was born just after the French revolution and grew up, studied and worked for the government during revolutionary times. He studied civil engineering but had a great interest in the physics of light. A major proponent of the wave theory of light, vs. the particle theory, he developed and eventually succeeded in constructing a lens specifically to fulfill the lighthouse's purpose: to shine a light far out at sea to enable sailors to know where they were. Read the book for the full details but something resonated with me since we are now in the French territory of Guadeloupe (like St. Martin and Martinique, divisions - territories of France).Fresnel did work for the government but his work on optics were initially independent until the government realized the potential of bright lighthouses. In today's world, he would have become a billionaire, patenting and selling his "lens" for tremendous profit. He could have marketed his product like an iPhone, since the whole world would eventually need many.The revolutionary French had (and may still have) a much more "liberal" view of scientific or basic humanitarian discoveries that should be shared by all, for the benefit of all. Fresnel and his optics, combined with French glass making were considered a general public good that would benefit mankind. Safe navigation, the saving of life and property in the pursuit of international trade seemed to be what a civil society needed. To be sure, others, namelythe British, took a more capitalistic approach to the problem. This is not to say that the French didn't capitalize on their achievements. But in either case, a wider impact was desired than to make a few bucks.And so, on top a concrete tower sits a small light, undoubtably surrounded by a small Fresnel lens, flashing green every four seconds, to signal seafarers that they are approaching St. Louis. A short bright flash? Sure, but it was and is a major step in expanding world trade, even at night. Sailing to foreign ports became safer, or in many cases possible.A few days ago, while we were in Pointe a Pitre, a huge container crane was delivered to the port authority. This was the fourth crane for the port. No doubt, the volume of international container traffic necessitated that additional crane, brought about by the help of a fellow French countryman, almost 150 years ago.