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probably on or near the same parallel of latitude. In 1663 it was due north of Paris : it then advanced westwardly till about 1819, when it returned eastwardly, in which direction it is still moving, and Bond supposes that the eastern limit will be reached in about 2140. There are so many resemblances and analogies between the secular and local distribution of the elements of terrestrial magnetism and heat that many persons are convinced that there is an intimate connection between them. The magnetic Pole lies near the region of greatest mean cold, and its course appears to be along the zone of lowest mean temperature. Auroras are believed to be essentially the results of magnetic disturbance, and originate, or at any rate are most abundant and energetic along a zone situated on and near the latitude of the magnetic Pole, which is probably that of greatest cold. It is inferred that no auroras are produced north of about 80°; in other words, that a person at the Pole would see the auroras on the southern sky. . The alternate heating and cooling of the Polar area, together with the great difference of temperature between the zone of greatest cold and the tropic of the northern hemisphere, would seem an adequate and probable cause for the generation of magnetic currents and storms. The auroras are observed to occur in cycles of varying

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intensity and frequency, lasting about eleven years ; and these variations seem to coincide with the variations in the number and importance of the spots on the sun, which also run through cycles of about eleven years. According to Mr. Meldrum the cyclones of the Indian Ocean also occur in eleven yearly cycles, during which their frequency and strength coincide with the condition of the solar spots. He also infers, from a careful examination of the meteorological reports of various places, that in the countries surrounding the Indian Ocean, such as Ceylon, Mauritius, Adelaide, &c., the rainfall periodicity corresponds with the cyclone periodicity; and that the years of maximum rainfall correspond with the years of maximum sun-spot frequency, while the years of minimum sun-spot frequency are those of minimum rainfall. These remarks suggest that the observation of the climatic and telluro-magnetic elements in Polar regions would lead to results of the highest scientific importance, which would also be of great practical benefit. This object alone should be a sufficient answer to those who want to know what use there may be in Polar research. The scientific man knows that no well-conducted inquiry is useless; and that the electric telegraph, the steam-engine, the galvanic battery, and numerous other inventions of unques

tionable practical importance originated in apparently useless inquiries.

The phenomena and distribution of Arctic ice are subjects worthy of investigation. It does not answer our purpose to detail the numerous observations made by Aretic voyagers. These observations indicate that the icebergș and ice-fields are loosened every summer, and sent drifting southward. These masses accumulatc most where there is most land, and by their melting they transfer the cold of higher latitudes to these more southern lands, and thus reduce their mean temperature. This has the effect of throwing the zone of greatest cold towards the south, especially where the lands advance far north. Observations upon the thickness of ice found each winter or each year at several localities would enable us to define the zone of greatest cold, and also infer from the thickness of the ice whether the regions around the Pole are warmer than in about 75° N. What are the regions of perennial ice ? for that there are such regions seems clear from the occurrence of sea ice in sheets formed of annual layers. These regions may be the true sources of the cold currents of the sea ; while the warm currents have a temperature of 40° or 45° F., and flowing from the north, may arise from the area where the sea is freed every year from ice by the

INTRODUCTORY CHAPTER.

summer heat. This is a conjecture, but, probably, as good a one as that advanced by some, that the Gulf Stream flows right across the Pole, that is, by Spitzbergen, and out again through Smith Sound and Behring Strait. The ice presses against the northern coasts, and where the passages to the south are narrow, blocks them up with ice. On either view the evidence is in favour of a continuous sea across the Pole ; for if the Gulf Stream flows across the polar area there must be sea, and where the water is not perceptibly cooled, probably open sea. The idea seems, however, to be preposterous. On the other hand the outflow of warm water in all directions from the Pole involves a large and open sea around the Pole. · In zoology and botany something has been done, but there is much more to do. The facts to be discovered cannot fail to have an important influence on all theories connected with their present and past distribution. This has been well shown in the case of botany by Dr. Hooker, whose remarks we quote. He referred to the existing flora of Greenland as being one of the most poverty-stricken in the globe, and yet possessed of unusual interest. “It consists of some 300 kinds of flowering plants (besides a very large number of mosses, algæ, lichens, &c.), and presented the following peculiarities :-(1.) The flowering plants were, almost without exception, natives of the Scandinavian peninsula. (2.) There was in the Greenland flora scarcely any admixture of American types, which, nevertheless, were found on the opposite coast of Labrador and the Polar Islands. (3.) A considerable proportion of the common Greenland plants were nowhere found in Labrador and the Polar Islands ; nor, indeed, elsewhere in the New World. (4.) The parts of Greenland south of the Arctic circle, though warmer than those north of it, and presenting a coast 400 miles long, contained scarcely any plants not found to the north of that circle. (5.) A considerable number of Scandinavian plants, which are not natives of Greenland, are nevertheless natives of Labrador and the Polar Islands. (6.) Certain Greenland and Scandinavian plants, which are nowhere found in the Polar plains, Labrador, or Canada, reappear at considerable elevations on the White, and the Alleghany, and other mountains of the United States. No other flora known to naturalists presents such a remarkable combination of peculiar features as this, and the only solution hitherto offered is not yet fully accepted. It is that the Scandinavian flora (which had been shown by himself to be one of the oldest on the globe,) did, during the warm period preceding the glacial—a period warmer thau the present- extend in force over

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