Of the lakes (Vötn), we shall inspect the two largest, the Thingvalla-vatn[84] and the Mý-vatn; and we shall sight a multitude of tarns and ponds, single and grouped. One peculiarity is noticed in many of the minor waters. In Iceland it is emphatically untrue that lakes without drains are salt or briny—a rule apparently applicable only to the temperate and tropical zones. Whether the phenomenon in the north arises from subterranean drainage through the fissures of the bed, or if it be due to absence of saline matter in the area of drainage, which is often modern lava too hard to be sensibly degraded, we have no means of determining: perhaps there is a union of both causes.
A remarkable feature is the abundance of warm water laid on by the hand of Nature; the map shows upwards of two hundred; and here perhaps the hottest springs of the Old World are found. Suffice it to say at present that they are divided into two main groups. The acidulous and acid-silica, which redden litmus-paper, depositing gypsum and sulphur, do not erupt: these are the “Öl-keldur” (ale springs) mentioned in the “Royal Mirror” of the twelfth century, and they are still locally and popularly distributed into three species. Some, like “martial” waters, inebriate from the abundance of carbonic acid gas; others when allowed to stand, part with their stimulating property; and others again when filled in rise elsewhere. The second class is the alkaline-silica, which restores the colour of litmus paper; it is often explosive, and it contains chiefly sodium and silica. In the valley of the Yellowstone River the springs are either (1.) Calcareous (alkaline), depositing carbonate of lime with sulphates of magnesia and soda, chloride of calcium, and a little silica; or (2.) Silicious (acid), containing 85:100 silica, chloride of magnesium, and only a trace of lime.
The Geysir (gusher)[85] is a spouting spring; the Reykirs (reekers) give forth steam; the Laug is a warm fountain which may serve as a bath; the Náma[86] (hole of hot water) is sulphurous and gaseous; the Hverr (cauldron), like its smaller congener the Ketill (kettle), is a tranquil, hot, and even boiling well or pool, it is also applied to mud springs; and the Makkaluber (the Italian “Salsa,” or “Hofetta,” and the American “Mud-puff”) is a miniature volcano of hissing, boiling bolus. Further details concerning the names and natures of these features will be given in the Journal.
§ 3. Climate.
The “cold of Iceland” is as proverbial as the “deserts of central Africa,” and both sayings are equally based upon unfacts. “Iceland, where the cold and winter are perpetual, and the cold scarce to be endured,” is what we read. But those who travel in the island find—(1.) that even in winter the temperature is rarely severe; (2.) that there are two distinct climates, on the north coast and in the southern country; and (3.) that the air, however unpleasant, is exceptionally wholesome.
1. The isotherms by no means follow the circles of latitude. The cold lines swerve away from, instead of passing through, Iceland, and show none of that severity which characterises Greenland and the northern parts of British America. As has long ago been observed,[87] the isotherm of F. 32°, the freezing point of water, which is that of Akureyri, varies 14° between southern Asiatic Russia (N. lat. 56°) and northern Norway (N. lat. 70°).
The mildness of the insular climate, and that of the easterly winds, which are too clear to come from warmer waters, are popularly attributed to the “great Gulf Stream.” This sea-river, we are told, “sweeping up from the south, brings with it a store of heat to bless the islanders, and so materially affects the island that in the south of Iceland the winter is not more severe than in Denmark.” The Gulf Stream is generally supposed to strike the south-western angle, and to flow along the southern shores; while others make it bifurcate off Reykjanes, hence one part subtends the north-western point or Land’s End of Iceland, where it meets the Polar and Arctic current, the other half embraces the southern shore, and both meet in the north Atlantic arm separating Iceland from Norway. Dufferin’s map shows the popular belief: the true Florida current, sweeping past the southern shore of Iceland, forks about Spitzbergen, sending off a branchlet to the west, and ends south of Novaya Zemlja. On the other hand, Dr Carpenter contends that the real “River in the Ocean” dies out in the mid-Atlantic. According to Dr Joseph Chavanne of Vienna (Mittheilungen, No. vii., 1874), the northern arm of the Gulf Stream, which flows between Bear Island and Novaya Zemlja, touches the northern coast of Asia, and eastward of the New Siberia Islands joins the western drift of the Kurosiwo. The other northern branch, which subtends the western coast of Spitzbergen and the Seven Islands, is submerged between the Polar currents, to reappear at the surface farther northward, and thence to lave the shores of the Arctic continent: the latter is thus washed by two warm streams, rendering the existence of perennial ice a sheer impossibility.
We may fairly question the existence of the Gulf Stream along the southern Icelandic shore, and doubt its bifurcation and subsequent reunion. This is not the place to discuss the subject of ocean circulation, a “discovery equal to that of the circulation of the blood,” first made by Professor Lenz of St Petersburg in 1845, based upon the second voyage of Kotzebue in 1823-26, and independently by Dr Carpenter during the cruise of the “Porcupine” (1869). Their aqueous movement corresponding with the aërial; and the mass of thermal equatorial waters travelling towards the poles, whilst the counter current sets in the inverse direction, would account for many phenomena yet unexplained, but it is still sub judice lis.[88] We may remark that the comparatively shallow seas between the British Islands and Iceland must accumulate heat, and that this fact perhaps suffices for what has been attributed to the Gulf Stream and to the general circulation. Thomas Bartolin (Acta Medica Havn. ad annum 1673) mechanically explains away the necessity of the former: “Aqua Insulas Ferroenses allabens, quamquam per se frigida sit, salsitudine tamen suâ, ex perpetuo motu, plerumque producit hyemem temperatam.” Hence the waters of Niagara are colder above than below the falls, and the ocean is warmer after a storm.
Practical men, especially mariners, in Iceland vigorously deny the existence of the Gulf Stream.[89] Captain Tvede, an intelligent and observing Dane whom we shall meet in the eastern regions, considers that the theory, like judicial phrenology and a host of pseudo-sciences, became popular because it generalises, formalises, and simplifies facts. He declares that a Gulf Stream, if it existed, would entangle the Greenland icebergs, and carry them to the southern coast of Iceland, which never happens. He asserts that a few miles south of Ingólfshöfði the Sea River is still warm, but that instead of striking the shore it trends directly north-eastwards to western Norway, sweeps round the continental North Cape, and here meets the icebergs from Spitzbergen and Jan Mayen. He has found himself in an ice-dock floating in water which showed 35° F.
Captain Tvede kindly gave me the following series of observations: