A hole of one foot square was accordingly cut right through the middle of the central stone in the sixth course; and at equal distances in the circumference were sunk eight other depressions of one foot square and six inches deep. A strong plug of hard marble, from the rocks near Plymouth, one foot square, and twenty-two inches long, was set with mortar in the central cavity, and driven firmly into it with wedges. As this course was thirteen inches high, it is evident that the marble plug which reached through it rose nine inches above the surface. Upon this was fixed the central stone of the next course, having a similar bore in its middle, bedded with mortar, and wedged as before. By this means, no force of the sea acting horizontally upon the central stone, unless it was able to cut in two the marble plug, could move it from its position; and the more effectually to prevent the stone from being lifted, in case its bed of mortar should chance to be destroyed, it was fixed down by four trenails. The stones surrounding the central were dove-tailed to it in the same manner as before, and thus one course rose above another, with no other interruption than the occasional violence of the waves or inclemency of the weather.
In every stage of the laborious and difficult work Smeaton himself was foremost. When it had proceeded so far as to present the appearance of a level platform, he could not deny himself the gratification of enjoying the limited promenade which it afforded; but making a false step, and being unable to recover himself, he fell over the brink of the work, and among the rocks on the west side. The tide having retired, he sustained no very serious injury; but he dislocated his thumb, and as no medical assistance could be procured, set it himself, and returned to his work. The incident is characteristic of the courage and tenacity of the man.
The ninth course was laid on the 30th of September, and the weather becoming boisterous, further operations were suspended for that year.
The following winter was very tempestuous, and it was the 12th of May before Smeaton and his workmen again saw the Eddystone. To their delight and surprise they found the entire work in the same condition as when they left it. The cement appeared to have become as hard as the stone itself, the whole being concreted into one solid mass.
Thenceforward the work made vigorous and successful progress, and, by September, the twenty-fourth course was reached and laid. This completed what is called “the Solid” part of the building, and formed the floor of the store-room; so that Smeaton had no reason to be dissatisfied with the operations of the season. But as he had long been meditating on the advantage to the public which would accrue if a light could be exhibited that very winter, he resolved on a vigorous effort to complete the store-room and erect a light above it.
The building, says an accurate authority,[29] had hitherto been carried up solid as high as there was any reason to imagine it would be subjected to the heavy rush of the sea; that is, to 35 feet 4 inches above its base, and 27 feet above the top of the rock, on the common spring-tide high-water mark. At this elevation it was reduced to 16 feet 8 inches diameter; and it was needful to make the best use of this space, and economize it to the utmost advantage consistent with the one primary and indispensable condition of strength. The rooms were built with a diameter of 12 feet 4 inches, having for the walls a thickness of 2 feet 2 inches. These walls were made of single blocks, and so shaped that a complete circle was formed by sixteen pieces, which were cramped together with iron, and also secured to the lower courses by marble plugs as before. To prevent any humidity penetrating through the vertical joints, flat stones were introduced into each, in such a manner as to be lodged partly in one stone and partly in another. With all these ingenious precautions, the twenty-eighth course was completely set on the 30th of September.
This, and the next course, received the vaulted floor, which formed at once the ceiling of the store-room, and the floor of the upper store-room. For additional security, therefore, a groove was cut round the upper surface of the course, in which was lodged a massive chain of iron. Upon this chain, in the groove, melted lead was poured, until the cavity was filled up. The next course was laid and completed in a similar manner; and by the 10th of October Smeaton had nearly perfected his arrangements for establishing a light and light-keepers at the Eddystone, when his hopes were suddenly stricken by a prohibition from the Trinity House, based upon legal difficulties. But this being at last removed, the work was recommenced for the next and last season on the 5th of July. On the 21st, the second floor was finished; on the 29th, the fortieth course was laid, and the third floor finished.