the Bell Rock Lighthouse was lit for the first time. Using 24 lanterns, it began flashing its warning light, 11 miles out off the east coast of Scotland atop a white stone tower rising over 30m (100ft) high. It was built by Robert Stevenson on a treacherous sandstone reef, which, except at low tides, lies submerged just beneath the waves. Since then, no repair has been necessary to its stonework. It is the oldest sea-washed lighthouse in existence. It was Stevenson's finest achievement, regarded by many as the finest lighthouse ever built, the most outstanding engineering achievement of the 19th century. In the centuries before, the dangerous Bell Rock had claimed thousands of lives, as vessels were wrecked on its razor-sharp serrated rocks.