Block Island Southeast Light

One of the most architecturally sophisticated lighthouses in America

Block Island Southeast Light stands on Mohegan Bluffs at the southeastern corner of Block Island, Rhode Island, and with a focal plane 261 feet above the sea it is the highest light in New England. Congress put up $9,000 for a light here in 1856, but the money went instead to a new North Light after a storm washed the old one away, and this one waited until 1874. Its lamp was first lit on 1 February 1875.

It was designed as a showpiece for the Lighthouse Board. Earlier lighthouses were generally plain and functional to look at, and this one is Gothic Revival in unpainted red brick: an octagonal tower on a granite foundation rising to a cast-iron parapet and an open gallery around the lantern, under a sixteen-sided copper roof with a ball ventilator and a lightning rod, joined by a connecting wing to a massive double keeper's house of two and a half storeys with a steeply pitched gable roof. The keeper had the north half and his assistants the south. When it became a National Historic Landmark in 1997 it was recognised as one of the most architecturally sophisticated lighthouses built in the United States in the 19th century, matched only by the Cleveland Light, demolished long ago.

The first optic was a first-order Fresnel lens about 12 feet tall, lit by four circular wicks burning lard oil until kerosene took over in the 1880s. In 1929 the lens was set to turn floating on a pool of mercury, driven first by clockwork and later by a small electric motor.

The bluffs are the trouble. They are eroding, and in 1990 the Coast Guard switched the light off and put a steel tower up nearby instead. In 1992 the building passed to the Southeast Lighthouse Foundation, and in 1993 the whole structure, some 2,000 tons of it, was moved back from the edge. It was relit in 1994 with a different first-order lens, made in 1856 and taken out of the Cape Lookout Lighthouse in North Carolina in 1980, and it now shows a green flash every 5 seconds, day and night. Restoration came in stages, and in July 2021 half of the keepers' duplex opened as the Southeast Lighthouse Museum. In summer the tower opens for guided tours to the top.