During the remainder of this month, no opportunity occurred for landing on the Rock, but the other departments of the service went forward with all possible dispatch. The Thirteenth course was nearly completed, and a part of the Fourteenth had been laid on the platform. The last of the moulds for the granite stones, to the height of 30 feet, had now been sent to the quarries of Aberdeen and Peterhead, where the Smeaton, and the hired sloop Alexander, were each loading a cargo. Mr Peter Logan had now left the quarries at Peterhead, where he had been for some months; and Alexander Davidson, one of the principal granite masons, appointed to attend the quarries at Aberdeen, was also soon to be removed from that station, to perform the same duty at the sandstone quarry of Mylnefield. Measures had likewise been taken for providing the necessary castings for the extension of the Railways to the western landing place at the Rock, which altogether were to include a range of about 800 feet. [Sidenote: Cast-iron Mushroom Anchors. Difficulty in procuring Trenails.] The uncertainty attending the fixing of the malleable iron shank into the large cast-iron head of the mushroom anchor, represented in Plate X. Fig. 4., from its liability to shake loose, had induced the writer to make trial of a mushroom anchor, made wholly of cast-iron, which was finished in a very complete manner by the Shotts Iron Company. At the same works, castings were also made for a set of new sheers for those broken in the month of September at the eastern landing creek, which answered all the purposes of a crane, as represented in Plate XI. The two new praam-boats building at Arbroath, had advanced considerably in the course of this month, and were now ready for the laying of the decks. Of all the materials connected with those which may be termed of a trifling nature, none was more difficult to be procured than the oaken trenails, for fixing the stones of the lower or solid part of the building while the work was in progress. After much correspondence with London and other ports, a considerable quantity was procured from trenail merchants of Wapping. But such was the demand for oak timber at this period, owing to the great supply wanted for the Navy, that it was not only at a considerable expence, from about L. 3 to L. 5 per hundred, but with great difficulty, that trenails of the dimensions wanted could be collected. It was found by a calculation, at this time, that 2544 trenails, from 20 to 26 inches in length, and 1¼ inches in diameter, and 3720 pairs of wedges, from 15 to 19 inches in length, 3 inches in breadth, and 1 inch in thickness at the top, would still be wanted. Fortunately, however, a great quantity of oak timber, suitable for trenails, was brought about this time from the Highland districts to Perth, for making the spokes of carriage-wheels. A supply of these was accordingly got, at a much cheaper rate than the ordinary