To the north of Mainland lies Yell, an Island twenty miles long, and nearly twelve broad, with several good harbours, or voes, as they are called by the inhabitants. Foula lies to the west of Mainland. It is about three miles long, and one and a half broad, and has only one harbour. This is called Ham, and is much resorted to by fishermen. Foula is thought by some to be that island which the ancients reckoned the ultimate limit of the habitable globe, and to which, therefore, they gave the appellation of “Ultima Thule.” This supposition is not founded solely on the mere analogy of the name, but also on the authority of Tacitus, who, speaking of the victories obtained by Agricola, and how far he penetrated northward, uses this expression: “_Insulas quas Orcadas vocant invenit domuitque; dispecta est et Thule quadamtenus._” _Tacit. Vit. Agric._ §10. But though the high land of Foula may be easily seen, in a clear day, from the northern part of the Orkneys, still it is doubtful whether this be really the island so called; because had the Roman fleet passed to the north of the Orkneys, they must have seen Mainland, Yell, and Unst, lying to the north of Foula. It may be further observed, that the description of Thule, as given by Pomp. Mela, lib. 3, §6, and Pliny, lib. 2, §75, and lib. 4, §16, is not reconcileable with the supposition of its being identical with Foula. At Thule, says Pomponius, “_Per Solstitium vero nullae (noctes sunt) quod tum jam manifestior non fulgorem modo sed sui quoque partem maximam ostentat._” This phenomenon, as Vossius has observed, can only belong to the 66th and 67th degree of latitude, and gives considerable countenance to the opinion of Thule being the same with Iceland. The statement of Pliny, who is not celebrated for geographical accuracy, is alike irreconcileable with either hypothesis, and belongs only to the Pole itself. These, (with the exception of Unst,) are all the islands belonging to Shetland that are worth notice, though they are nearly forty in number. About seventeen of these are inhabited; the rest being inconsiderable, are called Holms, and used only for pasture. On our arrival in Bressay Sound, there were anchored twenty-six ships from London, Hull, and Whitby, each of which, in turn, gave us three cheers, which we as often returned. All these ships were waiting for men, it being the place where most of the ships bound to the Greenland fishery call at to make up their complement. The Captain finding men very scarce, and wages high, did not engage any hands at Lerwick. We afterwards weighed anchor, and sailed out of the north entrance for Balti Sound, Island of Unst.