28o FRIDTJOF NANSEN. M.-N. Kl. 



strikint^' cxciuicss of llic flal plain so wiflcly cxtc-mlefl in lliis rcj^Mon, 

 seenis to indicate a kind ot" hase le\cl towarrls wliich the land has been 

 denuded, anrl cannot proliahK have been much above previous sea-level. 

 As far as I am aware, llic- ddcrnnnalions of j^rax'ily have not ^»"iven 

 consideral)le deficiencies in Sweden; this also indicates that the crust 

 has nearh' attainerj its level of e(|uilibrium. .\. (i. Hög'bom has drawn 

 my attention to W. Kamsay's statement in liis textbook (2nd erl., p. 14) 

 that "in Finland, Sweden, and in j^reat parts of Norway the observed 

 values of the acceleration of gravity show, as a rule, a rjeficiency 

 (= — 0.004 ^^'i'-)' while aloni;- the Norwegian coast, aiifl in southern 

 Norway as well as in Penmark the observerl values of the acceleration 

 are in most cases sliglulx' higher than the normal. 



Tlw I\casoiis -u'liy flic I'osti^Iacial Cn/sfal M oc'eiiiciits luvvc been retarded 

 in the Jvc'^ions round the Halt i c Sea and the Gulf of Bothnia. 



It seems to me to be prt>1)a]:)le that there are especially two reasons 

 wliy the postglacial upheaval is still continuing in the regions round the 

 Baltic Sea and the Gulf of Bothnia, wliile it was practically completed 

 long ago along most parts of the west and north coast of Fenno-Scandia. 



First. While the margin of the last glacial ice-cap retreated at a 

 comparatively early stage from the outer regions of the west and north 

 coast of Norway and the Kola Peninsula, if they were ever covered by 

 it, the interior parts of Fenno-Scandia were covered by ice for a much 

 longer time, and especially in the region west of Bottenviken, where the 

 lateglacial submergence was greatest, the last remnant of the ice-cap 

 remained till late in postglacial time. This would naturally retard the 

 upheaval of the land in those regions. 



Secofidly. Long after the disappearance of the ice-cap the land was 

 pressed down by the weight of the water-masses covering the submerged 

 land. First the Yoldia Sea was widely extended over great parts of 

 Sweden and Finland, submerging also a wide area across middle Sweden, 

 the regions of the great lakes, to Bohuslän, Halland, &c., and also some 

 part of south-eastern Norway. Later the water-masses of the Ancylus 

 Lake covered a wide area of eastern and southern Sweden and western 

 and southern Finland. During this period Bohuslän and the surrounding 

 regions were still greatl}' submerged, and also some part of south-eastern 

 Norway in the region of the Christiania Fjord. Even as late as the 

 Tapes-Littorina period considerable areas of land were still submerged 

 round the coasts of the Baltic and the Gulf of Bothnia. It is obvious 

 that the water covering the land weighed it down; but the addition of 

 load over the sea-floor outside was still greater. The floors of the Gulf 

 of Bothnia, the Baltic Sea, Kattegat, and Skagerrak were extensive parts 

 of the depressed area of the Fenno-Scandian region. Over these de- 



