" It is obvious, that in this method of dovetailing, while the slope of the rock was making good ; by cutting the steps (formed by Mr. Rudyerd) also into dovetails, it might be said, that the foundation-stones of every course were engrafted into, or rather rooted in, the rock ; which would not only keep all the stones in one course together, but prevent the courses themselves (as one stone) from moving or sliding upon each other. But after losing hold of the rock, by getting above it ; then, though every stone in the same course would be bonded in the strongest manner with every other, and might be considered as consisting of a single stone, which would weigh a considerable number of tons, and would be farther retained to the floor below by the cement, so that, when completed, the sea would have no action upon it but edgew..ys ; yet, as a force, it' sufficiently great, might move it, notwithstanding its weight, and the small hold of the sea upon it, and break the cement before time had given it that hardness which it might be expected to acquire afterwards ; I had formed more expedients than one for fixing the courses to one another, so as absolutely to prevent their shifting; but I shall not trouble my reader with a recital of those ex pedients at present, as they will more properly come in along with the reasons of my choice, in the detail of the actual proceedings." Mr. Smeaton made his first voyage to the Eddystone on the 2d of April, 1756, but was prevented from landing by the weather; but on the 5th of the same month he was more successful, and staid upon the rock about two hours and a half, during which time lie observed, "such traces of the situations of the irons fixed by Mr. Winstanley, as that it would not be difficult to make out his plan, and the position of the edifice ; from whence it appeared very probable that Winstanley's building was overset all together; and that it had torn up a portion of the rock itself with it, as far as the irons had been fastened in it." Tie also " perceived that Mr. Rudyerd's iron branches, as then called, were much smaller and shorter than he had described them to be at the bottom of his print ; that many of them were loose, and some broken and bent : and that, in regard to the steps, described to be cut upon the rock, there were only five of them, of which the traces were remaining : so that there was but one fiat or tread of a step above the centre of the house ; and the upper part of the surface of the rock above that, was a sloping plain. as it had been at first. Three steps, of the five now remaining, seemed to have been but tifintly cut, and the uppermost but one was so imperfect, that he supposed a large spawl or splinter had come from it; and this appeared the more probable, as the uppermost step was so shaken, that another large spawl might have been easily raised from it, by a slight action of a wedge. Above the uppermost step the rock seemed to be of a softer nature, was cracked in many places, and probably had received some damage from the fire. None of the steps appeared to have been cut with much regularity, either as to level or square; but to have all the marks of hurry upon them. In the centre of the house a slight footing was cut for the mast, suitable to a square of is inches, with large iron branches, answerable to two of its sides, and a small hole bored in the centre, of about I inch diameter, being 6 inches deep. By consulting Plate I., many of the above matters will be made apparent to the eye.
"I then," says Mr. Smeaton, "proceeded to try the degree in which the rock was workable, and flIund that from a flat surface, indifferently taken, I could, with a pick, sink a hollow at the rate of five cubic inches per minute ; and could cut or drill a hole with a jumper of l j inch diameter, at the rate of one inch deep in five minutes. I also tried a method of forcing two holes into one, by a square flat-faced bruiser, or pummel ; so that, if there should be occasion, I might be able to make a continued groove ; or let in an iron branch, in the manner of Mr. Rudycrd, and I had the satisfaction to find
that the whole succeeded to my wishes." In the choice of materials, Mr. Smeaton was determined in favour of moor-stone or granite, fur the outside work, and Portland stone for the inside. The latter was not eligible fur the outer surface, on account of its liability to be destroyed by a marine insect ; and the moor-stone was too hard and expensive in the working to admit of its being used through out the building.
By the 15th of May, Mr. Smeaton had made ten voyages of observation to the Eddystone, and then returned to Lon don, where having settled with the proprietors, he received his commission to proceed on the work. l Ie then went back to Plymouth, and, on the 3d of August, landed with the first company of workmen on the rock, where he began to fix the centre and lines of the work. A fter describing the difficulties under which he laboured from the uncertainty of the weather, and the necessity in which the workmen were placed, of returning to shore every tide, till a vessel fit for their recep tion could be properly moored off the rock, Mr. S. observes upon his preference of the use of picks and wedges for operating upon the rock, that "it might seem, at first sight, that a greater dispatch would have been by the use of gun powder, in blasting the rock, in the same manner as is usual in mines, and in procuring limestone from the marble rocks in the neighbourhood of Plymouth : but though this is a very ready method of working hard and close rocks, in proportion to the dispatch that could be made by picks and wedges; yet, as a rock always yields to gunpowder in the weakest part, and it is not always easy to know which part is weakest ; it might often have happened, it' that method had been pursued, that, instead of forming a dovetail recess, such as was required, the very points of confinement would have been lost. Besides, the great and sudden concussion of gun powder might possibly loosen some parts that it was more suitable to the general scheme should remain fast. For these reasons, I had previously determined to make no use of gunpowder for this purpose.
"On the 7th of September," says Mr. Smeaton, "I sent to Portland the draughts for the six foundation courses, that were to be employed in bringing the rock to a level ; which, with the draughts for eight that I had before. dispatched, completed the order for the whole quantity of' Portland stone to be used in the solid up to the entry door; being all that we could expect to set in place the next season. The rock was not indeed yet ready for completing the exact moulds for those stones that were to fit into the dovetails made in it ; but, by ordering the stones large enough, and being seappelled something near their proper form, it would prevent loss of time in waiting to get the true figure from the rock, as well as unnecessary waste.
" Nothing happened to prevent the companies from work ing every tide from the 27th of August, till the 14th of September, in which time they had worked one hundred and seventy-seven hours upon the rock. In this interval, having procured a carpenter to be applied to that purpose, I began to make the moulds for the exact cutting of the stones to their intended shapes. This was done by laying down, in chalk-lines upon the floor of a chamber, the proposed size and figure of each stone, being a portion of the plan at large of the intended course ; and the carpenter having prepared a quantity of battens, or slips of deal board, about three inches broad, and one inch thick, shot straight upon the edges by a plane; those battens being cut to lengths, and their edges adapted to the lines upon the floor, and properly fitted together, became the exact representatives of the pieces of stone whose figure was to be marked from them, when their beds were wrought to the intended parallel distance.