It is right, however, that I should mention here that the lenses, mirrors and zones are from the works of M. FRANÇOIS of Paris, whose name I shall afterwards have occasion to notice; and that the machinery was constructed to my entire satisfaction, and in a manner worthy of his reputation as a mechanician, by Mr JOHN MILNE of Edinburgh. ~Removal of the Barrack from the Rock.~ In such a situation as the Skerryvore, new wants were discovered every day; and each summer brought its round of smaller works, which the experience of the preceding winter had suggested. The Barrack was found very useful as a place of residence for the workmen, who were engaged in such needful works; and it was not until the summer of 1846, that it was taken to pieces and removed from the Rock, after having kept its place for six years. Its removal, however, was then thought advisable, as some of its fixtures, by the continual action of the weather, had become very loose and precarious; and, although a very small outlay would have made it almost as stable as at first, it was considered inexpedient to attempt to perpetuate a structure confessedly temporary in its nature, and the sudden destruction of which by the waves, seemed to involve some risk of injury to the Tower itself. ~Expense.~ The expense of erecting the Skerryvore Lighthouse, including the opening of quarries and forming wharfs at the quarries in Mull and also the Harbour in Tyree, was, as appears from the Account in the Appendix, L.86,977 : 17 : 7. In the course of the Summer of 1844, a marble tablet, bearing an inscription in letters of gold, was, by order of the Commissioners, placed over one of the windows in the Visiting Officers’ Room. With a representation of the Tablet and the Inscription, which, after acknowledging the hand of Almighty God in the success which attended the work, briefly sets forth the beneficent purposes for which the Lighthouse was erected and records the laying of the foundation-stone by his Grace the Duke of Argyll, I willingly close this most defective narrative of the work. [Illustration: IN SALUTEM OMNIUM NORTHERN LIGHTHOUSES A. D. O. M. AUCTORITATE . ET . CONCILIIS PHARORUM . SCOTIAE . COLLEGII HAEC . STRUCTA . FUIT . PHAROS CUJUS . DIRECTI . FLAMMA NAUTAE INFAMIBUS . HIS . SCOPULIS . ADHUC . MERITO . DETERRITI OPTATUM . PORTUM . RECTIUS . ADVENIRENT. JOANNES . DUX . DE . ARGYLL INSULARUM . ADJACENTIUM . DOMINUS LAPIDEM . AUSPICALEM . RITE . STATUIT DIE . IV . MENSIS . JULII . ANNO . IV . VICT. REG. M . D . C . C . C . X . L . OPERUM . MAGISTRO . ALANO . STEVENSON . L.L.B. _Engraved by W. & A.K. Johnston_] PART SECOND. NOTES ON THE ILLUMINATION OF LIGHTHOUSES. PART SECOND. NOTES ON THE ILLUMINATION OF LIGHTHOUSES, WITH SHORT NOTICES OF THEIR EARLY HISTORY. ~Early History.~