He secured the foundation with the utmost care. He divided the irregular surface of the rock into seven rather unequal stages, and cut thirty-six holes in these, to the depth of from twenty to thirty inches. These holes were six inches square at the top, gradually narrowing to five inches, and then again expanding and flattening to nine inches by three at the bottom. Into these dove-tailed holes strong iron bolts or branches were keyed; each bolt being fitted exactly in size to the hole it was intended to fill, and weighing from two to five hundredweight, according to its length and structure. The bolts made fast, Rudyerd proceeded to fix a course of squared oak timbers lengthwise upon the lowest step, so as to reach the level of the step above. Another set of timbers were then laid crosswise, so as to cover those already laid, and to raise the level surface to the height of the third stage. The third structure was again laid lengthwise, the fourth crosswise, and so on, alternately, until a basement of solid wood was secured, two courses higher than the highest point of the rock; all being fitted together and to the rock, by means of the bolts, as firmly as possible, and all, in their intersections with one another, being closely trenailed. The bolts originally let into the solid rock were perforated in their upper parts—some with three, and some with four holes; so that in every pair, collectively called a _branch_, there would be about seven holes. As the branches numbered thirty-six, there would be 252 holes, each about seven-eighths of an inch in diameter, and consequently as many large “bearded spikes” or “jag-bolts,” which, being driven through the branches into the solid timber, held the mass firmly down. * * * * * Rudyerd’s lighthouse is generally described as a timber edifice. This is not correct. Knowing that weight is best resisted and counteracted by weight, and to insure a sufficient amount of resistance, he combined with his courses of timber solid courses of Cornish granite, in this manner: the foundation was of oak for two courses; then came five courses of stone, each a foot in thickness, kept together by iron cramps; and then two courses more of timber. Thus was completed the basement. The remainder of the edifice, which rose to an elevation of 69 feet, on a base of 23 feet, was built of timber. The interior consisted of four rooms, one above the other; and above the topmost was the lantern—an octagon of 10 feet 6 inches in diameter, crowned by a ball of 2 feet 3 inches in diameter. The whole height of the lighthouse, from the lowest side of the rock to the top of the ball, was 92 feet. It was completely finished in 1709.