1867.] lORD SELKIBK SEA-WATER-LEVEL MARKS. 195 



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 infer- 

 ences to be drawn from these observations to others more com- 

 petent 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 LyeU 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. JSTow, had I seen Sir Charles 

 LyeU'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 Eudberg'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 Eudberg'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 

 met with that the horizontal line was cut at the water-level. Be- 

 sides this, if I am right in my conjecture that it is a loose stone, 

 and not a rocJc, 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 men- 

 tion 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 Eudberg'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. 



