This morning several casks of pozzolano, lime and sand were landed, to make mortar, in order to build round the lower edges of the foundation-pit. This being something like an approximation to the long wished-for commencement of building the Light-house, the artificers thought the opportunity too good to pass over in silence, and the casks were accordingly landed under a salute of three hearty cheers. At half past 6 P. M. the boats again landed upon the rock, but, even when the tide was at the lowest, the water stood to the depth of 18 inches upon the site of the building, and no work was done. This was rather a relief to the smiths, who having no irons to sharp, got rapidly forward with the necessary fixtures for the railways. [Sidenote: Thursday, 23d.] [Sidenote: Small ruble walls built instead of cofferdam.] The weather continued to be extremely mild, and the winds were generally from the eastward and southward, accompanied with thick and hazy weather, which, in communicating with the rock, was not only irksome but even dangerous. At 7 o’clock this morning, the tide proving more favourable, the artificers began to work. At 9 the rock was again overflowed, and the boats returned to the Tender after two hours’ work. Part of the operations of this morning’s tide consisted in building up the crevices and inequalities of the rock round the margin of the foundation, with pozzolano mortar, and the chips produced from the excavation, with a view to dam out the water. These little walls varied from six inches to eighteen inches in height; a small sluice or aperture being formed in one of them by which the water, during ebb-tide, was allowed to drain off. It formed part of the writer’s original design, as formerly noticed, to erect a cast-iron coffer-dam of about five feet in height, round the site of the building; but the surface of the rock was so irregular, that the difficulty of tightening it, and also of emptying the contained water, so as to get the benefit of it during ebb-tide, would have been so great, that, taking these circumstances into account, together, with the loss of time which would attend the erection of such a preparatory work, the idea of a coffer-dam was laid aside, soon after entering upon the actual execution of the work. [Sidenote: Inconveniencies of foggy weather.]