possible to penetrate them, except by the well-beaten footpaths of the Fuegians. The mountain peaks are of very compact greenstone, and highly magnetic, possessing the property of polarity in an extraordinary degree, the poles of the fragments broken away from the mass lying always in the line of the dipping needle, the whole forming a magnet of enormous magnitude, but not of sufficient power to produce any anomalous expressions from the instruments we employed; although, in one spot, we found the dipping needle gave an erroneous result of nearly half a degree.
The geological structure of Hermite Island, which Mr. McCormick examined with great diligence, is described in the Appendix; and the botanical account by Dr. Hooker, which possesses an unusual degree of interest, is inserted here.
"The scenery of Hermite Island so closely resembles that of many parts of the West of Scotland, that the two countries seem only to differ in the species of animals and plants which respectively characterise the northern and southern hemispheres. There are the same narrow arms of the sea, confined by high mountains, in Hermite Island, as form the salt-water lochs of Argyleshire; with similar deep and close bays, hemmed in by rocky, precipitous, and often inaccessible shores. The mountains rise at once from the water's edge, clothed for half their elevation with a low green forest, and crowned with rugged precipices and grey masses of rock; while torrents, heard,