Chap. VIII.
BRITAIN.
371
This building, finished in the year 1709, was repaired at various times, and answeredperfectly its purpose; but in December, 1755, it was totally destroyed by fire. The Earlof Macclesfield, then President of the Royal Society , being requested by the proprietors torecommend an engineer to reconstruct it, named Mr. John Smeaton , a philosophical in-strument maker, as a man capable of executing the work ; he was at that time in the northof England, but upon being made acquainted with his nomination, waited upon the pro-prietors, and having received their instructions, commenced his designs, though he admitsthat he was a total stranger to such structures. Smeaton has, however, informed usthat he reflected much, previously to making his design, upon the several structures thathad occupied the rock, and that he had a wish to retain as much of Rudyerd’s as was con-sistent with the different nature of the material he had in view; and he observes further,“ It appeared most evidently that had it not been for the moorstone courses, inlaid withthe frame of the building, and acting therein like the ballast of the ship, it had long agobeen overset, notwithstanding all the branches and iron work contrived to retain it; andthat in reality the violent agitation, rocking, or vibration, which the late building wassubject to, must have been owing to the narrowness of the base on which it rested, andwhich the quantity of vibration it had been constantly subject to, had rendered, in regardto its seat, in some degree rounding, like the rockers of a cradle. It seemed, therefore, aprimary point of improvement to procure, if possible, an enlargement of the base; it alsoseemed desirable to adhere strictly to the conical form, where the necessary consequencewould be, that the diameter of every part being proportionally increased by an enlargementof the base, the action of the sea upon the building would be greater in the same pro-portion ; but as the strength increases in proportion to the increased weight of the materials,the total absolute strength to resist the action of the sea would be greater by a proportionalenlargement of every part, but would require a greater quantity of materials; on the otherhand, if we could enlarge the base, and at the same time rather diminish than increase thesize of the waist and upper works; as great strength and stiffness would arise from alarger base, accompanied with a less resistance to the acting power, though consisting of aless quantity of materials, as if a similar conical figure had been preserved. A stone edificehaving been determined upon, the engineer gave to it the form of the waist or bole of alarge spreading oak; and made a model, by roughly turning a piece of wood, with a smalldegree of tapering, and then fitting it to the oblique surface of another block, which re-sembled that of the Eddystone rock; and found that by arranging the several curvescarefully, they could be firmly united, to form an efficient foundation. The model havinggiven ample satisfaction, it was ordered that the works should be proceeded with.
Fig. 373.