S8 Mr Johnston on the Elevation of 



levfel of the coasts of Sweden rest. Whatever can be accounted 

 for on the principle of depositions, is clearly no evidence of the 

 upraising of the land. Though, therefore, it has been argued 

 that some of the phenomena formerly quoted in support of the 

 change of level, such as the shallowing of harbours, the growth 

 of land, and the increasing elevation of certain islands, may be 

 accounted for by the supposed action of currents and rivers, 

 the fact itself remains untouched, in so far as it depends on the 

 apparent rising of rocks from the sea, or the change of the mean 

 level of the Baltic waters, in reference to the scarped granite 

 walls which confine them. The level of the sea is the only ele- 

 ment involved in this investigation, which we can regard as un- 

 changeable. If it can be made out, therefore, that the living rocks 

 on the coast, while they retain their relative position in regard 

 to each other, yet alter their level in regard to that of the water, 

 we can ascribe the change only to an elevation of the land. 

 Nor must we be deterred, as geologists too long were in regard 

 to the bay of Baiae, by any supposed stability even of a whole 

 peninsula, resting assured that nature, quiescent as she now is, 

 has still power enough to effect changes of a far more extensive 

 character. 



It occurs at once as an objection to the measurements of the 

 mean level of the Baltic, that though there are in that sea no 

 tides, yet the prevalence of easterly or westerly winds, by caus- 

 ing the current through the Sound and the Belts to set from the 

 east or the west, effects a change of the level of the whole sea 

 of several feet. This source of error did not escape the sur- 

 veyors in 1821, but by observations of the maximum and mi- 

 nimum very near approximations were made to the truth. If 

 we can obtain tolerably accurate determinations of the mean level 

 of the sea, on shores where the ebb and flow of the tide present 

 additional obstacles, the difficulty of determining that level in the 

 Baltic, cannot be fairly advanced as a reason for rejecting the 

 measurements obtained under the direction of the Swedish Aca- 

 demy. 



In the Gulf, and on the coast of Finland, proofs of a change 

 of level have also been observed, but they appear hitherto to be 

 less satisfactorily established, than on the west and northern 

 coasts of the Bothnian Gulf. It has even been proved, by the 



