in a valley, the lower part of which had gained considerably in extent, within the memory of persons now living, by the retreat of the waters. In descending to Ellelös on the eastern coast, opposite the island of Gulholmen, I observed shelly deposits about fifteen feet above the level of the sea, in which were many specimens of the Ostrea edulis, Saxicava rugosa, Cerithium reticulatum, and other shells, some of which I had seen at Uddevalla, and others cast up on the shores in Orust.

In regard to the island of Gulholmen, CELSIUS tells us that in his time forty pilots, none of whom were under sixty years of age, having been assembled there, had unanimously declared to one Mr. KALM that there was only fifteen feet depth of water in places where in their youth there had been eighteen feet. He also mentions that one of the pilots pointed out a small rock near Gulholmen, then rising two feet above the water, which, when he was a child, was not visible *.

The present inhabitants, as far as I conversed with them, are entirely ignorant of any such statements having been recorded a century ago; but on my demanding whether the water stood now at the same level as in their younger days, they unanimously declared that it did not. Mr. BRUNCRONA, in his memoir before cited, mentions that on an insulated rock called Gulleskär, near the harbour of Gulholmen, there was an iron ring to which ships were moored, and that this ring, when measured in 1820, was eight feet above the level of the water. Unfortunately, no particulars are given; and as both the chief pilot of 1820 and another who assisted him in the measurement were dead at the time of my visit, I could not ascertain with certainty from what point of the ring they had begun their measurement, nor the means they had taken to secure accuracy. Having obtained the assistance of JOHAN WUNSCH, now chief pilot, I found the point where the ring is fixed into the rock to be only seven feet five inches above the level of the sea, which was then declared to be at its usual level, a very slight wind only blowing from the north-north-west, and there being never any tides in the sea here. The iron ring, which has remained for more than half a century in its present place, is fifteen inches in diameter, and the top of it stands more than eighteen inches above the level of the rock when it is erect, in which position I found it, thus (see fig. 12), having been so placed for the sake

Fig. 12.

Summit of the Gulleskär, with the Ring.

* CELSIUS, Observations on the Diminution of the Waters of the Baltic and German Ocean.-Trans. Roy. Acad. of Sweden.

of drying the fresh paint, with which it had been just covered; but the islanders suppose the measure to have been taken from the bottom, or point where the staple enters the rock, which seems most probable. Curiosity led a great many of the inhabitants to accompany me; and when I declared that the height of the ring was seven inches less above the water than that recorded by BRUNCRONA, many of the older men with one accord pronounced this to be impossible, and said that the former observation must have been incorrect, for that the sea must, on the contrary, have fallen since 1820. Some of them affirmed that the pilot who received orders in 1820 to make the measurement was ignorant in what manner to proceed, the place of the ring not being perpendicularly over the water, and he having no instrument for levelling, so as to ascertain that the line which he first carried out from the ring was strictly horizontal. Whether there was any foundation for this charge I cannot pretend to decide; but I mention it as proving that the islanders believe that there is a change of level going on. It may be useful to those who may make future measurements to state what length of line it required to reach from the iron staple of the ring to the nearest point of the rock to which the sea comes up, this point being now exactly in the direction north-west and by north of the ring. I stretched the rope from one angle to another of the rock, not applying it to the surface of the intervening hollows, and found its length to be fifteen feet five inches and a half. As the Gulleskär, however, is by no means well chosen for the facility of observations, I had a new mark cut on the face of a vertical cliff on the south side of the harbour, about a hundred yards from the post-house. I subjoin a copy of the mark, the lower part of which was cut in my presence, and which the chief pilot promised to see completed. The horizontal line was cut six inches above the water-level, and the vertical line at the right end of it, six inches in length, was terminated at the bottom by a short cross line, which the surface of the water just covered. The vertical depth of water below the mark was four feet two inches and a half. I may suggest, that whenever horizontal lines or any marks are made, like that of St. Olof's Stone before mentioned, not at the level of the sea, but at a certain height above it, on a vertical face of rock, there should always be a perpendicular line cut down to the then existing level of the water, to facilitate subsequent observations and prevent mistakes. Marks cut at given heights above the standard level are perhaps the best, as they are not concealed by a temporary rise of the water.

C

Fig. 13.

L

18 187 34

Before leaving Gulholmen I visited the Skefverskär, an isolated rock which, according to the testimony of several old people, was always covered, except at very low water, about forty years ago. In their younger days, before the year 1799, when the present church of Gulholmen was built, they went to church at Morlanda, and passed near this rock, the exposure of the summit of which was a well-known sign to them of a particular state of the weather. This rock is now always seen except when the sea is very high. I found the highest point of it to be sixteen inches above the level

of the water; and its extreme length from east to west, including a detached point at one end, measured fifty-two feet four inches and a half.

From Gulholmen I went to Marstrand, an island about twenty miles to the south, in order to observe another of the marks enumerated by BRUNCRONA. I first re crossed the ferry at Svansund to the main land, and then passed to that of Tjufkil, which leads to Koon. On the shore at Tjufkil I found a bed of oysters and other shells, five or six feet thick, with pebbles intermixed, rising to the height of sixteen feet or more above the water. The oysters, which were in great number, all belonged to the Ostrea edulis, which is taken on this coast; and the other shells were the same as at Uddevalla and Ellelös, with the addition of Anomia striata. This shelly deposit has been overwhelmed by a great fall of rock from the steep heights of gneiss behind, some of the fragments which cover the shells being about nine feet square.

Not far from the harbour at Marstrand is an artificial channel, which, in the year 1770, was cut through an isthmus which formerly connected two parts of Koon island. The excavation was made through a mass of clay and sand with shells, similar to that of Tjufkil, already mentioned; so that there can be no doubt that there must originally have been a natural passage in this place. One Captain CONSTANT, who superintended the digging of the channel in 1770, caused a mark, of which the following is a sketch, to be hewn on the face of a vertical rock of micaceous schist on the shore of Koon, nearly opposite Marstrand.

Fig. 14.

Mark at Koon Island, near Marstrand.

ÅR 1770

An horizontal line, ten inches long, is seen twenty-one inches below the bottom of the last cipher. This line I found to be just ten inches above the level of the

water. My observation was made on the 19th of July 1834, sixty-four years after the mark was cut. Now my boatmen stated that the horizontal line was originally intended to express the lowest level to which the sea fell at the time of digging the Koon canal; and this information was confirmed by Mr. O. J. WESTBeck, who resides in the immediate neighbourhood. On my applying to this gentleman to learn whether the water at the time of my observation might be considered as unusually low, he said that as the wind was easterly, the sea was certainly below its mean level, but it had by no means reached its extreme point of depression, for there still was water in the Koon canal, immediately opposite his villa; whereas, after the prevalence of a strong easterly wind for two days, the sea falls so low that certain parts of this canal are dried up. He suggested, therefore, that by measuring the depth of water in those parts of the canal which dry up, and adding that depth to the ten inches which I had already obtained below the mark only half an hour before, I should ascertain the point of extreme low water as compared to that of 1770. We accordingly found that the water in the places alluded to was fourteen inches deep; so that the lowest water now is two feet below the maximum of depression sixty-four years ago. Mr. WESTBECK said that he had always heard from his father that the mark, which was cut the year he was born, was intended to express the lowest level of the sea during the digging of the canal in 1770.

I have already stated that there is no tide on the coast here, a circumstance which seems very extraordinary; but all the pilots and seamen agree in asserting the fact. A strong wind off the shore causes the water to fall two or three feet, and to rise as much if it be in the opposite direction. Notwithstanding these occasional oscillations, the inhabitants pretend to determine whether the sea is two or three inches above or below its standard level. I was shown here, as at other places, rocks which forty or fifty years ago could rarely be seen, but are now permanently above water. I was also told of numerous rocky channels where boats could once pass, but which had now grown too shallow, and of meadows which were yielding from time to time a larger quantity of hay, in consequence of their increased extension on the side towards the sea.

'I know not how much further to the south the same signs of a rise of the land have been observed, but it is certain that the narrow frith in which the port of Gothenburg is situated has been gradually filling up, in such a manner as would happen if the same cause of change was cooperating there with the deposition of river-sediment. It is well known that in the sixteenth century the ancient port was placed twenty miles further up, and called Lödese; and this was afterwards removed further down, and called New Lödese, to distinguish it from what remained of the more ancient harbour. But now the newer of these places is called Gammle Staden, or the old town, and is a mile or more above Gothenburg.

On the banks of the river at Gothenburg I found a deposit of blue clay, filled with a great variety of recent marine shells. Among others, Lutraria compressa; Mactra

subtruncata, very abundant; Tellina solidula; Donax trunculus? DILLWYN; Cyprina Islandica, Venus gallina, Cardium edule, Littorina littorea, Turritella terebra, Rostellaria pes pelicani, and Buccinum reticulatum. This part of the estuary is now always filled with fresh water, except on rare occasions, and for a short time, when a strong wind drives the sea up the river, and causes the water to rise six feet, in which case it becomes brackish. At different heights above the sea, in the valley of the Götha Elf, between Gothenburg and Trolhättan, marine shells have been found similar to those of Uddevalla.

Some persons who have been long resident in Gothenburg pointed out to me, as a proof that the water was falling there, that the rocks several feet above the highest water-mark were bare and uncoloured, by which they meant that no lichens grew upon them.

A similar remark had been made to me at Tjufkil, Svansund, and other places on this coast. It seems probable that some species of lichen may require a much longer time to establish themselves on newly exposed rocks than others; and I could observe distinctly, near Gothenburg, that some kinds approached nearer the water's edge than others, and that the variety of species became greater and the colour different on ascending to greater heights. It would therefore be an interesting point for a geologist sufficiently skilled in botany to determine whether the extent of the lichens and mosses downwards towards the water on this coast, where the rocks are supposed to be always rising, presents different phenomena from the line of vegetation on other coasts, where the relative level of the land and sea is known to have remained stationary.

On many parts of the eastern coast, above described, the sea freezes in severe winters in the Skär; that is to say, among the rocks and islets which skirt the main land, and where there is almost always still water. As I have before mentioned the accounts which I received of the transporting power of ice in the Gulf of Bothnia, it may be well to state some facts bearing on the same subject which I learnt at Gothenburg. In the harbour of that port there are a great number of strong wooden piles, called dolphins, three or four feet in circumference, the lower parts of which are sunk to a considerable depth in the mud, and firmly fixed in it, so that vessels may be moored to their tops. As these dolphins are annually frozen in, it is found necessary to break the ice round them; but sometimes this has been neglected, and Mr. HARRISON, the English Vice-Consul, informed me, that on such occasions he has known a great number of the piles drawn up together out of the mud six feet perpendicular, a rise of the river having caused the ice to float up to that amount.

Mr. WESTBECK of Marstrand, to whom I have already alluded, mentioned to me, that having been formerly employed in the Swedish Diving Company for thirty years, he had opportunities of witnessing the extraordinary power of ice to lift up from the bottom of the sea and remove to a distance very heavy masses. In two instances the ice collected round sunken vessels which were under his charge, and having frozen