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Show 270 TIERRA DEL FUEGO. June, 18~4. answering to our December, January, and February, which three months appear to be the coldest, and the ~ean o~ these is 33° .08.* Dublin is nearly in the same lat1tude m the northern hemisphere as Port Famine is in the southern, and we will take its temperature as a means of comparison. Mean of Summer Winter Difference. Summer and Latitudes. Temperature· Temperature Wiuter. Dublint . . . 530 21' N. 590 .54 39° .2 20° .34 49o .37 Port Famine 53 38' S. 50 33 .08 16 .92 41 .54 Difference 0 17' 9 .54 6 .12 3 .42 7 .83 It will be seen by this that the temperature at Port Famine is very considerably lower, both during summer and winter, than at Dublin, and that at the former the difference between the seasons is not so great, or that the climate is there more equable, It seems the general opinion of those who have visited this country, that the frosts are not so severe or so long as in England. The sealers say that throughout the year they wear the same quantity of clothing. Nevertheless Captain King states, that during the winter of 1828 the temperature was once as low as t 12° .6. I have drawn up these rough and approximate statements merely for the sake of illustrating some of the following remarks. '~~< This mean must be a little too low, because the whole of August is not included. I see Von Buch says," we can hardly assign to Saltenfiord, Norway (in lat. 67°, or 13° 22' nearer the pole than Port Famine) a higher mean temperature than 34°, nor a higher temperature for the warm month of July than 57°.8." (Travels through Norway, p. 123.) Captain King gives as the mean for February, which probably is the hottest month at Port Famine, only at 51 o .I. Some observations made at the Falkland Islands {2° 13' north of Port Famine) which are often quoted, give as the mean for the whole year 47° .3, and for the summer 53° .1. These results are very much higher than what I should have anticipated, from the climate of the neighbouring mainland. t This line is taken from Barton's Lectures on the Geography of Plants, :t: In this wretched climate, subject to such extreme cold, is it not most wonderful, that human beings should be able to exist unclothed and without shelter? June, 1834. VEGETA'J.'ION. The kind of climate here described appears to be common to the southern parts of the whole of the southern hemisphere. Although so inhospitable to our feelings, and to most of the plants from the warmer parts of Europe, yet it is most favourable to the native vegetation. The forests, which cover the entire country between the latitudes of 38° and 45°, rival in luxuriance those of the glowing intertropical regions. Whilst in Chiloe (lat. 42°) I could almost have fancied myself in Brazil. Stately trees of many kinds, with smooth and highly coloured barks, are loaded by parasitical plants of the monocotyledonous structure ; large and elegant ferns are numerous; and arborescent grasses intwine the trees into one entangled mass, to the height of thirty or forty feet above the ground. Palm-trees grow in lat. 37° ; an arborescent grass very like a bamboo in 40° ; and another closely-allied kind, of great length but not erect, even as far south as 45°. In another part of this same hemisphere, which has so uniform a character owing to its large proportional area of sea, Forster found parasitical orchideous plants living south of lat. 45° in New Zealand. Tree-ferns thrive luxuriantly near Hobart Town, in Van Diemen's Land.. I measured one there which was exactly SL'r feet in circumference; and its height from the ground to the base of the fronds appeared to be very little under twenty. Mr. Brown says* "an arborescent species of the same genus (Dicksonia) was found by Forster, in New Zealand, at Dusky Bay, in nearly 46° S., the highest latitude in which tree-ferns have yet been observed. It is remarkable that, although they have so considerable a range in the southern hemisphere, no tree-fern has been found beyond the northern tropic: a distribution in the two hemispheres somewhat similar to this has been already noticed respecting the Orchid ere that are parasitical on trees." Even in Tierra del Fuego, Captain King describes the "vegetation thriving most luxuriantly, and large woody stem- • Appendix to Flinder's Voyage, pp. 575 and 584. |