Eddystone, a group of gneiss rocks, daily submerged by the tide, in the English Channel, 9 miles off the Cornish coast, and 14 SSW. of Plymouth Breakwater. The rocks lie in 50° 10' 54" N. lat., and 4° 15' 53" W. long., and have 12 to 150 fathoms water around. The frequent shipwrecks on these rocks led to the erection of a wooden lighthouse, 100 feet high, by Winstanley, 1696-1700. The great storm of 20th November 1703 completely washed it away, with the architect. A similar lighthouse (1706-9) was burned in 1755. The next, constructed by Smeaton in 1757-59, was built of blocks, generally one to two tons weight, of Portland oolite, encased in granite, the granite being dovetailed into the solid rock, and each block into its neighbours. The tower, 85 feet high, had a diameter of 26 3/4 feet at the base, and 15 feet at the top. The light was visible at a distance of 13 miles. As the rock on which it was built is undermined by the action of the waves, the foundation of another was laid on a different part of the reef in 1879. The new lighthouse, completed in 1882 by Sir James N. Douglass, F.R.S., is, like its predecessor, ingeniously dovetailed throughout. Its dioptric apparatus gives, at an elevation of 133 feet, a light equal to 159,600 candles, and visible to a distance of 17 1/2 miles. Smeaton's lighthouse was taken down to the level of the first room as soon as the new one was completed, the removed upper portion being re-erected on Plymouth Hoe.