Historian Michael Gannon says that first public works project in today's America - a lighted watchtower to guide Spanish supply ships into St. Augustine - was a dismal failure.

   But the beacon for America's oldest port city would continue to guide ships along St. Augustine's shore through more than four centuries to the present day, its tower transforming over the years from wood, to coquina, to brick, granite, cast iron, and bronze; its beacon from torch, to whale oil, to lard oil, to electric light projected through a Fresnel lens; its height from 35, to 85, to 165 feet.

   St. Augustine founder Pedro Menendez ordered the first, a 35-foot wooden structure to guide Spanish ships from established ports in the Caribbean. In 1994, a determined volunteer organization, the Junior Service League, completed restoration of its last transformation, making it one of America's most historically correct, active maritime aids.

   During the British occupation of 1763-1784, a 50-foot wooden lookout was added. That tower would survive until 1880 before crumbling into the waters of Salt Run, where its remains can still be seen today.

   In 1823, the watchtower's location became part of a network of lighthouses to protect the nation's commerce.

   In 1871, with tides and storms eating into the land beneath the tower, Congress appropriated $60,000 for the construction of a new lighthouse. October 15, 1874, a new, 165-foot lighthouse was completed, and the light atop the old Spanish watchtower was permanently extinguished.

   Lighthouses are identified by mariners through two visual means unique to each lighthouse - one for day and one for night. St. Augustine's daymark is its black and white spiral with a red lantern atop. The tower's nightmark is in its light. From 1874 to 1936, St. Augustine's nightmark was one bright flash every three minutes. When electricity was installed in 1936, the speed of rotation increased to one fixed flash every thirty seconds.