sufficient to cover any casualty in the final dressing of the block by the masons at Hynish, and which allowance was generally equal to a film of rock about 1¹⁄₂ inch in depth. The blocks thus roughly formed were shipped for Hynish, distant about 26 miles, through a tempestuous sea, open to the full reach of the Atlantic towards the south-west, sometimes in a small vessel called the “Queen,” belonging to the Commissioners, and sometimes in undecked boats of 16 tons, belonging to the adventurous men of Tyree. The freight usually paid was 5s. a ton, and yet the whole of the blocks for the Lighthouse Tower, and many of those used in the pier at Hynish, were laid down to the number of about 5000, at the rate of 2s. 1¹⁄₂d. per cubic foot, including all the expense of building barracks, opening quarries, freight of stones, and the expense of building and maintaining the small vessel called the “Queen,” above noticed. The stone of the Mull quarries is a reddish or flesh-coloured granite, in which felspar predominates. About 13·66 cubic feet weigh a ton, and it is not quite so hard as the granite of Aberdeen. [19] Whether from any inflection of the Celtic _Rhua_, or _Roy_, or directly from the Italian _Rosso_, it would, perhaps, be impossible to determine. ~Observations on the quarrying of granite.~ As I am not aware that any professional work contains a detailed description of the quarrying of granite, some observations on that subject may not be unacceptable in this place; and I therefore propose, at the risk of appearing somewhat prolix, to give a pretty minute account of the mode of opening and working a granite quarry, more especially as practised by us at North Bay. Having laid bare the rock of earth, gravel, or other loose matter (which operation, as I have elsewhere mentioned, is in Scotland technically called _terring_), and having swept or washed clean the surface of the rock so as to have a good view of the natural seams or joints which traverse it, the next step is to fix the best place for putting in a bore or mine. In selecting the position of the bore, the direction of the seams and veins of the rock must be duly considered, with a view to employ the force of the explosion to the greatest advantage in separating the natural joints or beds of the rock, instead of shattering the solid _masses_ or _posts_ (as they are called in the language of the quarry) into shivers or fragments.