490 



NATURE 



and Rodskiir, and some other places, a sinking has taken 

 place during the last twenty years, amounting to 07 

 centimetre a year. This sinking is, however, at all 

 events at Safvo, as far as can be ascertained from personal 

 observation, of a quite local nature. At Calmar, on the 

 other hand, as already shown by Dr. Siljestrom, no 

 change whatever has taken place since the beginning of 

 the century. 



From Stockholm northwards there are about thirty 

 water-marks, and here, too, the rising predominates, 

 although it varies often in localities very near each other ; 

 but a careful discussion of the observations seems to have 

 established that the rising has been on the decrease 

 during the last century. During the last period it 

 amounted at Stockholm to o"5 centimetre a year ; at 

 Celsius's old water-mark, at Lofgrundet, off Gefle, to 0*9 

 centimetre ; at Chydenius's mark at Ratan to nearly i 

 centimetre ; at Bergo, on the Finnish side of the Gulf, 

 to I centimetre ; and at the mark cut by Augustin 

 Ehrensvjird, August 21, 1754, on a rock at Hango 

 (Finland), to o"6 centimetre. Therefore, a considerable 

 rising, varying from 0*5 to I'l metre per century has taken 

 place in this part of the Baltic. 



The above facts, gathered by Dr. Holmstrom, form the 

 last contribution to our practical knowledge of the old 

 water decrease problem, and many decades must now 

 elapse before fresh data can be obtained for further obser- 

 vations upon these changes in the earth's crust — changes 

 which appear to us to take a long time, but which, 

 geologically reckoned, are very rapid. 



If the problem of the land-rising is taken in the same 

 extent in which it was first raised by Swedenborg, it may 

 be divided in two problems, certainly related, but widely 

 separated, and both of pre-eminent importance to the 

 geological history of the earth, viz. (i) the question of the 

 changes of level to which the sea or the hydrosphere of 

 the earth has been subjected in historical times ; (2) the 

 question of changes in the level of the sea during the 

 immense length of the geological ages. 



As regards the first, it must be considered fully 

 demonstrated, to the student free from preconceived 

 opinions, (i) that in several places along the coast of 

 Sweden, during the lapse of a few generations, a con- 

 siderable rising of the land has taken place, not only in 

 the Baltic, but also on the west coast ; (2) that this rising 

 varies in different localities, and is in some places entirely 

 wanting. 



These facts cannot possibly be explained, as some 

 students have attempted, simply by maintaining that the 

 sea-level of the Baltic lies above that of the seas beyond, 

 and that a gradual levelling takes place ; as in that case 

 no rising could take place on the west coast. If we, 

 therefore, as is always advisable in natural researches, 

 take the actual observations as basis for our theories, we 

 are compelled to assume that in some places on the 

 Swedish coast a gradual upheaval of the solid funda- 

 mental rock really takes place, although some portion of 

 the apparent rising may no doubt be ascribed to a decrease 

 of the water in the Baltic. That such a decrease does 

 occur is probable, but when the student of science refers 

 to it, he should bear in mind that it is only an hypothesis, 

 as yet far from being proved. 



Several circumstances seem certainly to speak against 

 the trustworthiness of the observations founded on the 

 water-marks. Prof. P. A. Gadd, for instance, remarks that 

 often there have been found, close to a mark indicating a 

 rising of the land from 3 to 4 feet in a century, trees 300 

 years old standing close by the water's edge — i.e. in 

 places which, when the tree was only a shoot, would 

 have been several feet under water, and this argument 

 has been repeated without contradiction by Lyell, Erd- 

 mann, Suess, and others. But it is forgotten, when this 

 is used as an argument against the land-rising theory, 

 that the tree during a period comprising centuries may 



have sunk through its own weight and through the 

 washing away by rain of the earth at its roots, peculiari- 

 ties which cannot be unknown to the horticulturist who has 

 planted trees on earthy eminences in parks. Indeed it is 

 self-evident that among the thousands of trees by our 

 shores there must be some which could strike their roots 

 and thrive just in such a spot. Viking mounds, memorial 

 stones, and buildings by the shore might be subjected to 

 similar sinking, the water-marks carved in the solid 

 crystalline rock only being trustworthy as evidence 

 in questions about secular changes in the earth's 

 strata. 



Another argument against these observations on the 

 coasts of Scandinavia is that these changes of level, 

 if they do really take place, cannot possibly be confined 

 to this country alone, but must be observable in other 

 parts of the world. But any certain counterpart to 

 the land-rising in Sweden is not known anywhere, not 

 even on the North Sea coast of Norway, nor along the 

 Atlantic border, where foundations of monuments dating 

 from the time of Caesar still remain intact. The weight 

 of the latter argument is, however, greatly reduced when 

 we bear in mind that observations such as those made in 

 Sweden could not possibly be effected on a coast exposed 

 to the ocean, where, in consequence of the tide, the level 

 of the sea varies diurnally and alters with the directiop 

 and force of the wind — changes which so far exceed the 

 land-rising here referred to that they would entirely 

 obscure it. Besides, as regards old buildings, only those 

 built carefully of granite and resting on the solid rock 

 can be taken into account in this discussion. It is, more- 

 over, possible that such an elevation of the land as that 

 in Scandinavia takes place only in districts where the 

 rocks consist of granite or crystalline schist. The Medi- 

 terranean being a sea with a mouth far more narrow 

 than that of the Baltic, is unsuitable for the settlement 

 of such questions. On the west coast of Europe, again, 

 the tide is so great that similar observations there would 

 be very difficult. Neither are the sandy shores of 

 Holland and Germany suited for such observations, 

 and the east coast of America has hardly a history long 

 enough for such researches. This applies in a still greater 

 degree to the west coast of America and the coast of 

 Australasia. The volcanic shores of the Pacific Ocean 

 are but little suited for the observation of such changes 

 of the level of the sea. That no rising of the land along 

 the coasts of the oceans has been observed is therefore 

 capable of explanation. 



But even accepting the theory that a slow secular dis- 

 turbance of the level of the shoi-e-line does take place in 

 some localities we are obliged to confess that the geo- 

 logists at present cannot advance any certain proof of 

 a general change in the level of the sea having occurred 

 in historical times. Any general decrease or increase of 

 the volume of water in the sea in historical times has not 

 been proved. The case is, however, different when it is a 

 question of changes during ages not measured by those 

 of man, but by those of the earth, i.e. by the measure of 

 time, which no doubt bears the same proportion to our 

 years and rcenturies as our terrestrial measures bear to 

 astronomical distances. For in all parts of the globe, 

 as well at the equator as near the Poles, we find rocks 

 which incontestably have, during former geological ages, 

 been formed below the sea, although now lying above it. 

 There is not a shade of doubt about this. And one of the 

 reasons why the geologist has with such great interest 

 studied the question of land-rising in Sweden is that he 

 hopes to derive from the small changes that take place 

 before our eyes an insight into the causes of the great 

 ones. With regret, however, we must confess that our 

 success has yet been very slight. There does not yet 

 exist any satisfactory theory of the origin of the beds of 

 chalk and clay, a thousand feet in thickness, containing 

 fossils of unmistakable sea animals, which are found high 



