4308 tons, while the same mass of Mull stone would weigh 4252 tons, leaving a difference of not more than 156 tons in favour of the Hynish stone. The mortar employed in the building was composed of equal parts of Aberdda lime and Pozzolano earth, and was therefore identical, in its composition, with that used by Smeaton at the Eddystone. Not having been able, after searching the neighbouring islands, to obtain good sand, I found it inexpedient to adopt the proportion of equal parts of lime, sand, and Pozzolano, which were so successfully used at the Bell Rock; but so perfect was the adhesion of the mortar used at the Skerryvore, that in that mass of 800 tons only two small leaks were discernible, which being _ripped_ or opened with an _iron_, and allowed to run dry, were afterwards carefully repointed, and have never since shewn the slightest symptoms of leaking. CHAPTER VII. OPERATIONS OF 1841. ~Hynish workyard.~ The workyard at Hynish presented a very busy scene during the summer and winter of 1840; and the desolation and misery of the surrounding hamlets of Tyree seemed to enhance the satisfaction of looking on our small colony, where about 150 souls were collected in a neat quadrangle of cleanly houses, conspicuous by their chimnies and windows amongst the hovels of the poor Hebrideans, who generally make no outlet for the smoke in their gloomy dwellings, but permit it to escape by the doors. The regular meals and comfortable lodgings and the cleanly and energetic habits of the Lowland workmen, whose days were spent in toil and their evenings, most generally, in the sober recreations of reading and singing, formed a cheering contrast to the listless, dispirited, and squalid look of the poor Celts, who have none of the comforts of civilized life and are equally ignorant of the value of time and the pleasures of activity.