MARCH 6, 1867.

Robert Henry Scott, Esq., M.A., Hon. Sec. R.G.S.I., Director of the Meteorological Department of the Board of Trade; and Elijah Walton, Esq., 144 Kent-road, S.E., were elected Fellows.

The following communications were read:

1. On some SEA-WATER-LEVEL MARKS on the COAST of Sweden. By the Right Hon. the EARL of SELKIRK, F.R.S., F.G.S.

DURING a short tour in Sweden in the summer of 1866 I had an opportunity of examining the sea-marks, which are supposed to show some change in the relative level of land and water, both in the Gulf of Bothnia and on the west coast among the islands off Göteborg. The general belief among the people on the coast that the land is rising, or, as they term it, the water receding, adds a good deal to the difficulty of the inquiry, every one naturally wishing to show something to corroborate the general belief.

The first marks I saw were two, both off the harbour of Gefle. On Tuesday, 3rd July, 1866, I went in a sailing-boat, with two pilots and a young gentleman of the place, who spoke English well, and who volunteered to accompany me. We had a brisk wind from west and south-west, and made a quick run over to Löfgrund, which is one of the outer range of islets off the harbour, and is, I suppose, some twelve English miles from the town. I was at once shown the mark described by Sir Charles Lyell, which is said to have been cut by one Rudberg, a pilot. I call it "Rudberg's mark." It is a date, 1731, with a line under it; and two feet six inches (old Swedish measure) lower down there is another date, 1831, with another line under it; but the last figure is not very distinct, and may be a 4; and when I saw it, the water was one foot below this lower line. It appears to me that the mark is not upon a rock, but upon a boulder-stone; and I should, though I feel much hesitation in differing from such an authority as Sir C. Lyell, have called it gneiss rather than mica-schist. My reasons for believing it to be a stone, not a rock are:-that all the rocks I saw in the neighbourhood, where I could distinctly see that they were rocks, were much more smoothed and rounded off at the top; and also that nearly every other stone I saw in the island was sandstone, or conglomerate, of a reddish or brown colour. I could see nothing that I could be sure was rock in situ in the Island of Löfgrund. The bay is rather on the north than the east side of the island, and the place where the mark is seems to me open to the Gulf of Bothnia. There can be no doubt, however, that it is the same mark seen by Sir Charles Lyell: it is near the shore of the bay opposite to where the houses are; the place is a summer station for pilots and fishermen, and is uninhabited in winter, but is sometimes visited by parties coming over the ice. I was told that sometimes no open water is to be seen here at all, and that the ice becomes from five to eight feet thick; this I conceive must be by one sheet sliding over the top of another; it is said, too, to carry

about stones of several hundredweight frozen into the ice. The pilots said that the water was somewhat low in the harbour this day. I also found the marks of pitch oozing from the conglomerate, described by Sir Charles Lyell, on one or two large blocks that lie on the outer (or eastern) shore of the island.

After spending an hour on the island, I sailed again for St. Olof's Stone, in Edskösund. This is an enormous boulder, some forty or fifty feet high above the water; it lies a few yards from the shore, which is covered with loose stones of no great size; it is of gneiss, I think; and at no great distance (say 50 to 100 yards) there are rocks in situ of the same, very much rounded by glacial action, but a good deal split, apparently by subsequent frost. A date (1820) is clearly seen upon it, on the side of the stone furthest from the shore near which it lies; but there is no horizontal line near the date. A little to the right of a person looking at it, and about two feet lower than the date, there is a horizontal line, which can be more easily felt than seen. This line, as near as I could measure (but the water was not quite still) was fifteen inches above the water. I could not find out whether this was the mark Sir Charles Lyell saw. The horizontal line is upon the most projecting part of the stone, which overhangs below.

The

On the 5th July I went to examine the mark on the Island of Gräsö, put there by a person of the name of Olof Flumen, who was superintendent of the pilots on the coast, and was, I believe, a Swedish naval officer. This I call Olof Flumen's mark. Island of Gräsö is a long and not very broad island that runs along the coast, having a navigable channel within it. The north end of the island is some eight English miles from the town of Oregrund, which is nearly abreast of the middle of the island. The mark is some four miles to the southward of the town, and just about the place where the channel is narrowest and most encumbered with rocks and islands. It is on the perpendicular face of a small precipice that looks rather as if it had been quarried (but I do not believe that it has been so); it is exactly as Sir Charles Lyell describes it, and is on this day (5th July, 1866) about six inches (not more than seven certainly) above the level of the water, which was not quite still. Sir Charles Lyell, in 1834, saw it five inches above the water. Though there is no perceptible lunar tide here, there is a good deal of rise and fall of the water. I was told that about two years ago it rose two feet and a half in a few hours; a heavy gale followed, but not on the same day. Near Oregrund I saw a lagoon, which had a narrow channel about thirty yards long, that seemed to have been cleared out to let a small boat pass. On the 5th July the water was running into the lagoon from the sea, on the 6th the current was running the other way-in neither case strongly. This was all I observed connected with the sea-marks on the east coast of Sweden.

On the west coast I examined four marks: the one furthest to the north is one put upon a rock by Sir Charles Lyell at the pilot-station at Gulholmen, about eighteen to twenty English miles

to the north of Marstrand. It is upon a rock at the entrance of a small creek that runs up close to the village, and is to the south of the Post-house, as Sir Charles calls it, which is the only tolerable house in the village, and is also the Inn as well as the Steam-boat Agency. On the 18th July, 1866, the water-line belonging to the mark was just three inches above the surface of the water. The innkeeper, who showed me the mark, said that he considered the water at present rather high for the season; but the men of a sailing-boat, in which I returned to Marstrand, said, on the contrary, that they thought it rather low. The other three marks I saw were near Marstrand, though none were on the Island of Marstrand itself. The first I saw, which was the one furthest to the north, is on a rock This mark is a just abreast of the northernmost part of the town. row of four jumper-holes, each about an inch deep, and placed between 1 and 2 inches apart in a horizontal row, with the date 1821 over them. I call it the Four-Holes Mark. I have since heard that it was put there by one Nils Brunskrona; there is an N.B. over it. On the 17th July, 1866, the water was just up at the hole; on the 19th it was six inches lower, as near as I could measure it; but, the rock not being perpendicular, it was difficult to measure accurately. This mark is not mentioned at all by Sir Charles Lyell. The rock upon which this mark is placed is a hard gneiss rock, and as little like anything bituminous as any rock I ever saw; and yet it had the appearance of black pitch oozing from it. I thought at first that some recently pitched boat must have rubbed against it; On looking but the pitch seemed too much ingrained for that. closer, however, I saw that the rocks bore marks of fire, and I found afterwards that on May Day, or Midsummer, or some such festival, they were in the habit of burning a tar-barrel now and then on the top of this rock. The other two marks were put, as I was told, by a Captain Cronstadt, a Swedish engineer, officer (and I shall call them Captain Cronstad's marks), in the year (AR) 1770, when taking levels with a view to cutting a canal, which, however, was never finished, and for which another is now substituted. The first I saw was on the island of Bakkaholm, close to the landing-place, and just facing the village of Marstrand; it is upon a very shelving rock, nearly flat, in fact, which made it difficult to measure; but the mark was, on the 19th July, seven inches perpendicular above the actual level of the water, and about fifteen above a place to which, from the appearance of the weed, it seems generally to retire in summer. This mark seems not to have been observed by Sir Charles Lyell. The last mark I saw was the one observed by Sir Charles Lyell, and is, if I am not mistaken in my estimate of the distance, an English mile from the town of Marstrand, on the island that faces the town at the opposite side of the harbour, called the Island of Koon. It is at the foot of a precipice some fifty feet high, I suppose, south-east of the town. The letters are shaped in the way that he describes, owing to the way in which the gneiss is stratified, for the convenience of carving the letters on a material of uniform hardWithout his measurement I could never ness and similar grain.

have found the proper mark. I found a line just twenty-one inches below the cypher, and that line is now (19th July, 1866) just seven inches above the water-level. He gives it on 19th July, 1834, as being ten inches above the water; so that the water is actually three inches higher against the rock than when Sir Charles Lyell observed it. There is another line, apparently cut since, at the distance of nine inches above the old one; and there is another sixteen inches below it, and nine below the present water-level; and there is a date between them (1847); but I did not hear who had put it there or cut these lines. I think the old line and the date must have been refreshed at the same time. The water must have been a good deal lower when this last line was cut than now (19th July, 1866); for I can scarcely imagine a person cutting this mark under the water, nor can I divine an object for doing so. These are all the marks I saw.

I heard a curious story at Marstrand à propos of change of level. There is an island called Steningsön, on which stands a church called Norum. A hill not far off partly conceals the church from the top of another hill beyond; both hills are, and always have been, bare rocks at the top. It is said by some of the old people that half a century ago or more only the top of the spire was visible; but now the roof of the church can be seen. The gentleman who, in reply to my inquiries, gave me the names of the places, and to whom the story was familiar, though he seemed inclined to laugh at it, hinted that the level of a man's head above the ground was not the same at ten years old and at twenty. I could hear nothing of any earthquakes ever having been felt in this part of Sweden.

Among some people in Sweden an idea prevails that while the north part of the country is rising from the sea, the south is sinking under it; but if I am not mistaken, the state of the water in the ditch of the citadel of Malmö contradicts this idea, as there seems to have been no serious change of level during the centuries this ditch has existed; if I am not misinformed, it was here that Hepburn, Earl of Bothwell, ended his days in confinement.

Though not immediately connected with the sea-marks, I may mention another very curious phenomenon that I saw at Marstrand. The rocks here are hard gneiss, and very much marked with those scratches generally attributed to glacial action. A number of round holes exist, like those sometimes worked by the water near waterfalls, or by the waves on the sea-shore, and which are made, in fact, by loose stones moved by the current or the waves. They were of different sizes, from a foot and a half to above six feet in diameter. I could not ascertain the depth, as the bottom was full either of water or of earth and rubbish, which I had no means of removing; but I saw one that was certainly over six feet deep. Were I to theorize about how the water that moved the stones that bored these holes was itself set in motion, I would suggest that the glaciers that may have made the scratches may have had holes analogous to those called "moulins," I believe, in Switzerland, down which water falls with some force, and which I believe are always in the same

place, though the glacier moves forward bodily; but this is mere conjecture.

I have now detailed all that I have seen of these marks, and what I heard from people on the spot. I would wish to leave the inferences to be drawn from these observations to others more competent to reason on these subjects; but if I am asked what I think of them myself, I must say that they prove nothing. The truth is that the daily and weekly alterations in the level of the water caused by changes of the wind, and sometimes, I believe, by winds. not felt at the spot where the change of level takes place, are so very considerable that anything that may have taken place in thirty years is almost imperceptible in comparison. For instance, I was at Marstrand, and saw the water up to the four-holes mark on the 17th July, 1866; on the 18th I saw the water three inches below the mark Sir Charles Lyell cut at Gulholmen, which lies only twenty miles to the northward; and on the 19th the water was six inches below the four-holes mark. Now, had I seen Sir Charles Lyell's mark on the 17th it is quite possible that I might have seen the water exactly at his mark; and it is equally possible that on the 19th I should have found it six inches lower. From this I infer that until the average level is more clearly ascertained, no inference can be drawn from these marks. When I first saw the marks at Gefle, especially Rudberg's mark, I imagined that there was proof positive of the regular change of level; but there are considerable elements of uncertainty about them. The mark on St. Olof's stone is so indistinct, that it can only be of use in connexion with other marks; and there are two circumstances connected with Rudberg's mark that interfere materially with any certain inference from it. There is no written document I could hear of, to ascertain the fact that the original mark was not placed to mark some unusually high level of the water; indeed there is no clear evidence that I have Imet with that the horizontal line was cut at the water-level. Besides this, if I am right in my conjecture that it is a loose stone, and not a rock, may not that stone rest upon a shelving rock, up which the pressure of the ice from the Gulf of Bothnia may have moved it? If a stone, it is clearly too large to have been lifted from its place by being frozen into any modern ice-field; but the pressure of a mass of ice extending for many miles, coming in urged by a strong gale from the Gulf of Bothnia, may easily be conceived to have moved it a little way up an inclined plane. I merely mention these things as being sufficiently possible to throw a great amount of doubt over the inference to be drawn from the present position of this mark relatively to the level of the water.

I think I saw fir and spruce-trees, near the east coast of Sweden, growing so little above the present level of the water that, had it been as much higher in 1731 as Rudberg's mark would indicate, they must have begun to grow from under water, a thing of course impossible. But to ascertain this accurately I should have required a levelling instrument, as well as permission to cut the trees to find out their age.