The Contractors for this gigantic project are Messrs J. and C. Rigby, London. G. C. Dobson, Esq., C.E., is the Resident Engineer; G. F. Lyster, Esq., C.E., Assistant Engineer; Mr. J. Radford, General Manager; and Mr. R. Cousins, Engineer for the Contractors. The works were commenced in January, 1848; and they have been going on since then as rapidly as it was possible to proceed. Twelve months were occupied in laying down rails to the quarries, erecting stages, and making other necessary preparations for the works; since which, an average of 1,300 men have been employed on the works. The broad gauge has been used for the railway, by which means the contractors, are enabled to bring larger pieces of stone than the narrow gauge could accommodate. There are two quarries used, one called Moelfry Quarry, from which limestone is produced, and the other is, in fact, the Holyhead Mountain, from the sides of which the materials for the works are taken. A railway is formed from the extensive quarry on the side of the mountain to the Soldier’s Point, and Salt Island. Wooden staging is run out into the sea; strong long balks or piles are fixed in a vertical position in the water, resting on the base; these are secured with beams placed longitudinally so as to form a base for the construction of the railway. The top of the staging is considerably above high-water mark. The depth of the sea at low water, on the line of the breakwater, varies from 20 to 40 feet; the tide rising, on an average, to a further height of 17 feet in spring, and 7 feet in neaps. Along the top of the staging are railways capable of sustaining the weight of a locomotive engine and a number of waggons loaded. In the erection of these stages the utmost care has been evinced by the contractors and engineers to prevent accident; in order to obtain this object, no expense has been spared; the machinery and staging being of the best and strongest description. The work may be described as consisting of two breakwaters, one to the north, (Soldier’s Point,) and the other to east, (Salt Island.) The quarries are contiguous to the works, and here a great number of the workmen are employed; they are, perhaps, the most extensive in the country, and it is not an hypothesis to say that in no quarries extant is work of such magnitude and rapidity carried on. Holyhead Mountain, which affords the source of supply, consists of schistus quartz of so hard a nature that the tools of the workmen will scarcely touch it, and its edges will cut glass. The quarrying begun with the foot of the mountain slope, and it has progressed into the mountain until an elevation of 130 feet perpendicular has been attained. The scene at the quarries exhibits one of the most active pictures of industry, from the width of the workings, and the number of labourers employed.