successive rise of the land; or in other words, during the gradual conversion of part of the gulf into land. I conceive that they may have been formed in those tracts where a marine current, flowing as now, during the spring when the ice and snow melt, from north to south, came in contact with flooded rivers rushing from the continent, or from the west, charged with gravel, sand, and mud. According to this view, these large Swedish ridges may be compared to smaller banks known to have been formed within the last five or six centuries on the eastern coast of England, at points where a prevailing marine current from the north meets rivers descending from the interior, or from the east. In such situations the river, instead of entering the sea in a straight line, is deflected at a right angle, and runs from north to south between the land and the new-formed sand-bank. The deep narrow breaches which occasionally occur in many of these ridges in Sweden, precisely resemble those which a flooded river or an inundation from the sea sometimes makes through our smaller banks above alluded to. If this explanation be admitted, I conceive that the steep escarpments often presented on both sides of the oasar or ridges of sand, may be almost entirely due to their original form, and not to subsequent denudation. As to the manner in which the erratic blocks have been lodged on the highest parts of these sand-banks, I fully adopt the opinion of those who believe them to have been carried by ice, respecting the agency of which I shall have more to say in another place.

The low meadows near the town of Upsala are not many feet above the level of Lake Maeler, the most northern arm of which reaches near to that place, which is distant about fifty miles from Södertelje, before alluded to, at the south-eastern extremity of the same lake. If the opinion, therefore, of the rise of the land be well founded, the whole of Lake Maeler, and the low lands adjoining, must have been covered with salt water at no very remote period in history. Professor WAHLENBERG pointed out to me a meadow to the south of Upsala in which the Glaux maritima and the Triglochin maritimus now flourish, plants which inhabit salt marshes bordering the sea. These same species have, it is true, been found in the interior of Germany and France near saline springs; but in the country of Upsala there are no salt springs; and this botanical phenomenon seems to confirm the opinion that the salt waters have only receded in very modern times from these lands, and that the rains have not yet had time to dissolve and wash away all the salt which may have been originally precipitated when this tract was laid dry,

op

The next region which I examined was the coast near Oregrund, a port about forty miles north-east of Upsala. During the survey of 1820, before alluded to, a mark was made near this place on the rocky cliffs of Gräsö, a long narrow island which lies posite to Oregrund. On my visit to this island I was accompanied by Lieut. OLOF FLUMEN, a gentleman of the pilotage establishment, who cut the mark in 1820. It is much to be regretted that neither he nor any other observer, as far as I could learn,

Fig. 9.

had visited these spots since the marks were made. No place could have been better chosen for the purpose: the letters and lines, which are still as fresh as if newly made, have been cut upon the vertical face of a cliff of gneiss, which is free from lichens, and which plunges to the depth of about three fathoms perpendicularly beneath the water. I subjoin a sketch (fig. 9.) which I made of the rock and mark as they appeared on the 1st of July 1834. A vein of granite, composed of felspar and quartz, traverses the gneiss in an oblique direction above the mark. The rock is stated by BRUNCRONA to be in latitude 60° 18' N. It is situated at the south of Strandtorpet and north of Käringsundet. The length of the horizontal line is twenty inches and a half; the figures express that the mark was cut on the 13th day of the ninth month (September) in the year 1820, and the runic letters at the beginning and end of the line are the initials of OLOF FLUMEN.

18 13 20

9

Mark at Gräsö near Oregrund.

At the above date the horizontal line was exactly at the level of the sea on a calm day, when the water was supposed to be at its standard level. When I visited the place on the 1st of July 1834, the line was five inches and a half above the surface of the water; and Lieutenant FLUMEN and the seamen thought that a slight wind which was then blowing from the north-north-west, directly down the sound between Oregrund and Gräsö, caused the water to be an inch or two higher than it would have been had the sea been as perfectly calm as on the day preceding my visit. I found the pilots, both here and at other places on this coast, to be of opinion, that notwithstanding the fluctuations of level caused by the wind, a person well accustomed to this sea can decide whether, on a particular day, the water is an inch or two above or below its standard level. There had been several calm days without wind before I arrived at Oregrund, and I was assured that the sea was in a state of rest similar to that of the day which had been chosen fourteen years before for making the mark. Before we came to the spot, both Lieutenant FLUMEN and the boatmen expressed their persuasion that I should find the sea below the mark, because they declared that either the waters of the gulf were always sinking, or the land on this coast was gradually rising. To confirm this opinion the sailors pointed out several rocks which they well remembered to have been barely covered with water in their younger days, or about forty years ago, but which now rise between one and two feet above the water. Among others they took me to a small insulated rock in the sea, opposite Domaskärsund, which they recollected to have once been nearly two feet lower, at which time the neighbouring channel, which I saw nearly dry, had allowed a loaded

boat to pass. So strong is the conviction of the fishermen here, and of the seafaring inhabitants generally, that a gradual change of level, to the amount of three feet or more in a century, is taking place, that they seem to feel no interest whatever in the confirmation of the fact afforded by artificial marks, for they observed to me that they can point out innumerable natural marks in support of the change; and they mentioned this as if it rendered any additional evidence quite superfluous.

The sea deepens rapidly near the coast at Oregrund, and there is twenty-eight fathoms water in the bay. Along the shore is a broad band of bare gneiss traversed by granite veins, which ramify in every direction, and consist chiefly of felspar in large crystals. In many places this sloping band of bare rock, having a smooth surface, extends up for a hundred paces from the sea, covered only with a scanty coating of lichens. The gneiss, where it approaches within eighteen paces of the sea, is so smooth and polished that it is difficult to walk upon it. The surface swells into those rounded flattened forms which are so common in the forests in the interior of Sweden, where grass is frequently unable to establish itself on so hard a foundation. Not even lichens can grow in some parts where veins and beds of quartz appear; but trees take root in the clefts of the granite and gneiss, rising amidst vast erratic blocks, resembling those which, in equal numbers and of equal dimensions, crowd the greater part of the shores and islands of the Bothnian gulf.

From Oregrund I went on to Gefle, about forty miles to the north-west. In a low part of the intervening country, near the village of Skjerplinge, I came to a large tract of stiff blue clay, like that near Upsala, covered with sand six or eight feet deep. In the clay I found the Mytilus edulis and the Tellina Baltica. I was informed that marine shells are met with abundantly at a much higher level in a hill of sand near Skjerplinge, where also, according to tradition, a large iron ring, such as ships are attached to, was formerly found fixed in the soil.

My attention was repeatedly called to low pastures from one to three miles inland, where the old inhabitants or their fathers remembered that boats and ships had sailed. The traveller would not have suspected such recent conversions of sea into terra firma; but there are few regions where a valley newly gained from the sea may so rapidly assume an air of considerable antiquity. Every small island and rock off this coast is covered with wood, and it only requires that the intervening channels and fiords should dry up and become overspread with green turf for the country to wear at once an inland aspect, with open glades and plains surrounded by wellwooded heights.

Among other stories of wrecked vessels found in the interior, I was told at Gefle that a vessel and an anchor had been found in a hill of sand and gravel at Uggleby, sixteen miles from the sea, in the parish of that name. Colonel HÄLLSTROM tells me that similar traditions are common in Finland, and that a wreck is said to have been found there at Laihela, two miles from the sea.

On both sides of the river at Gefle I found land gained from the sea, within the

memory of persons now living; and its gradual extension here, and in other places to the north and south, is attributed by the natives to a slow but constant change in the relative level of land and sea. In this place the deposition of fluviatile sediment must cooperate with other causes; but the shallowing of the water and its conversion into land are too universal to be explained by sedimentary accumulations alone. Preparations are making to remove the harbour farther from the town, in consequence, as I was assured, of the continued fall of the water rendering it every year more difficult for ships to reach the ancient wharfs.

I visited two marks near Gefle, one of them cut in 1731 in the island of Löfgrund, twelve miles north-east of that port, and another made in 1820, about six miles farther north. The first of these marks (that of Löfgrund *) was carved by one RUDBERG in 1731, on a fixed rock of mica-schist, in the middle of a small sheltered bay on the east side of the island. The mica-schist is very hard and full of garnets, the highest part of the rock being only four feet above the water, and its length and breadth about fourteen feet. There is a depth of water of about seven feet and a half on the side where the mark is made. The annexed sketch (fig. 10.) will give some idea of the outline of that side of the rock and of the mark.

The horizontal line, which is somewhat irregularly cut, is known to have been originally made at the mean water-level. When I measured it on the 3rd of July 1834, this line was two feet six inches and a half above the mean level of the water; but as the wind was blowing from the east-north-east, the chief pilot of Gefle, who accompanied me, declared that I ought to add at least four inches more in order to express the full difference of the ancient as compared to the present level of the sea. It will appear that I had afterwards good reason to believe that this estimate was not exaggerated. Even when this allowance is made, the fall, in the space of somewhat more than a century, is not quite equal to three feet. There is a lower horizontal mark two feet five inches long, irregular and without any date, which, when I ex* Sometimes called Löfgrundet, the final et being the definite article in Swedish.

amined it, was washed and almost covered by the ripple on the surface of the water. It is not enumerated by BRUNCRONA as among those which were cut in 1820; but my boatmen and the fishermen on the island said it was cut in 1820. Although occasionally covered by the small waves, it was one inch and a half above the mean level of the water, and would probably have been four inches or more above it on a calm day.

It has been observed that lichens grow nearly to the water's edge on the rocks skirting the Gulf of Bothnia, and certainly the lower border of this line of vegetation often appears very distinct when viewed at a short distance; the rock below, where it is alternately wet and dry, remaining of its natural colour, which is usually very much contrasted with that of the surface, where it is coated with lichens. Now it has been proposed to measure and note the distance of this line of vegetation above the sea, and then to determine, after a certain lapse of years, the rate of elevation of the land, by observing how much lower the lichens have descended. With a view of furnishing data to future observers for such comparisons, I endeavoured, at Löfgrundet and other places, to ascertain the height of this line of vegetation, but without success, for it always appeared to me undefinable. Not only is it very uneven, but sometimes, after passing over a space of bare rock, we come down again to some straggling lichens growing luxuriantly nearly to the water's edge.

tum.

VON BUCH mentions in his Travels* that he found a large quantity of fine-grained red sandstone, used as a building-stone, at Gefle, containing small nodules of asphalHe was told that these stones were found nowhere in situ, but were thrown up by the sea upon the skär, or that line of rocks and islands which bounds the coast off Gefle. I found the shore of the isle of Löfgrund strewed over with these schistose red-sandstone blocks. They have the form of large flat slabs, with angular edges, as if they had been just taken from a quarry. They were exposed to a hot sun, and the black pitchy matter was oozing out abundantly from numerous pores. The planes of stratification presented those undulations called ripple-marks. On my inquiring from whence they came, I was assured by the fishermen that a fresh supply of such masses was brought to the coast from time to time by the sea. I remarked that their size was such that the waves could not have power to move them, that there were no rocks like them in the neighbourhood, and that they were not rounded by attrition as if rolled at the bottom of the sea. One of the fishermen replied that the ice might have brought them, and he undertook to show me much larger blocks which had been stranded recently on different parts of the skär. I accordingly went to a small island called Hvitgrund in order to see proofs of this fact, and there I observed blocks of red granite, five or six feet in diameter, perfectly free from lichens, amidst other blocks of various sizes which were coloured grey, white, and black, by a coating of these plants. The sailors named other spots where I might see much larger blocks, perfectly bare, or only beginning to be covered, amidst

*Vol. ii. chap. v. French edition, p. 303.