Another very curious optical phenomenon presents itself, partly in clear, partly in thin foggy weather. The islands lying at a distance Irom the continent appear to approach to the spectator, and to increase in size. They form to the eye various and peculiar groups, very different from their proper shape. At other moments they appear to i hang in the air. If this phenomenon appears with respect to the islands which lie in the south, southerly winds will follow; if the object be in the west, westerly winds may be expected. The winds decrease generally after sun set.
Fire-balls are rarely seen in this country, although one was observed in the year 1808, taking a direction from north-west to south-east. The comet of 1807 was first ob served on the 4th of October, in the north-west ; and that of 1811 on the 41.h of September, in the north, and disap peared the 14th January. Thunder is very seldom heal,., but sometimes flashes of lightning ale seen. The air is extremely pure and light; the rains are not of long con tinuance ; and the heat, particularly in the inlets, is asto nishing, being caused principally by the reflection of the solar beams from' the mountains. The saline particles of the sea-water are frequently found crystallised on the shores. In the month of July, the thermometer of Reau mur rises in the shade to 24 degrees, (86° of Fahrenheit). The moskitos (culex nipiens) are at that time as painful and troublesome as in a southern climate.
The ice, which embarrasses the polar regions, and clic. turbs the navigation, is of different kinds, some of it being of fresh water, some of salt water. The former is clear, very hard, brittle, having an appearance entirely glassy. and presenting sometimes colours of the finest pale eine rald green, or the brightest sky-blue ; when cut in pieces, the fragments are as sharp edged as those of rock crystal. The ice of salt water has the appearance of frozen snow. is greyish white, not transparent, and has generaliy a clam my coherency ; when very thin, it is flexible to a certain degree, under the step of a man. It coagulates in small spheroidal particles; whereas that of fresh water presents rather acicular and prismatic forms. The frcsh-water ice forms tremendous masses and mountains of different mag nitudes, and wonderful shapes, sometimes rising more than 500 feet over the surface of the water. The salt ice oc curs always in flakes, called by the mariners ice fields, sometimes of many thousand fathoms in length and breadth, divided by fissures, but following close to each other. These flakes of driving ice are not found so large in Davis Straits, as between the east coast of Greenland and Spitz bergen. The surface of the salt ice is generally covered
with a crystalline crust, deposited by hoar frost or snow ; it has a mealy or sandy surface, and becomes brackish by the tides. The salt ice never forms large mountains. On the shores, however, where the sea freezes, the mass be comes enlarged by the effect of the. tides, and by stormy weather, which breaks the ice, and heaps it up.
Ice mountains are formed, during a series of years, in the inlets and bays, in valleys, or on precipitous rocks reach ing to the sea. As they melt in summer at the base, where they are in contact with the rock, they get rift ; and at last, losing their points of support, they plunge into the sea with a thundering noise ; an awful and imposing spec tacle, which may be seen in the lee Bay, near Disko island, particularly at the time of the tides. These moun tains very often enclose vegetable substances, earth, and stones; and are sometimes so large as to reach to the bot tom of the sea, a depth of more than 300 fathoms, until they lose somewhat of their mass, and roll over. Immense. masses of ice are driven out from the Ice Bay in the tides, at the time of high water, covering the sea of Disko Bay, to a distance of many miles.
The driving ice which comes from Spitzbergen, is gene rally seen at Cape Farewell in the month of May, setting over to the eastern coast of Davis Straits; but it. returns again with south-west and west winds, filling all the bays and inlets of the south of Greenland, and is again thrown out from the land by the easterly winds. This ice is al ways followed.byimpenetrable fogs; a circumstance, which makes it much more dangerdus to navigators. The spe cific gravity of the ice depends upon its density or porosi ty.
The floating timber, mostly pine, which comes with the ice round Cape Farewell, affords great relief both to the poor Greenlanders and the European settlers. It furnishes materials to the -natives to roof their houses, to support their tents, to strengthen their canoes, to shaft their instru meats, and to prepare their utensils. It supplies the Europeans with building materials and fuel. It is very difficult to say from what country these timbers dome; undoubtedly from a very remote land, washed away from shores covered with forests. The timber is always much injured, generally without bark or roots, and great part of it is worm-eaten by the Pholas teredo, (Teredo navalis, Lin.) It is mostly found in the small bays of those islands which are nearest to the open.sea.