was less prosperous. This decline begins already in the last stage 

 of the Bronze-age, which according to Montelius occurred 600 — 500 

 b. C. About this time another significant alteration took place. Mon- 

 telius, 1 has proved that the amber trade then took up a new route. 

 During the Bronze-age amber was chiefly brought from the North 

 Sea coast and transported on the western trade-routes, the Elbe, 

 the Weser a. s. o. to the Mediterranean countries. From 700 b. C. 

 the western route for this trade was exchanged for the eastern trade- 

 route along the Vistula a. s. o. which indicates that the supply of 

 amber was thenceforth derived from the Baltic instead of from the N. Sea. 

 The cause of this was, according to my opinion, the following: 



The climatic deterioration which set in towards the end of the 

 Bronze-age resembled that which occurred 1800 years later at the 

 end of the Middle-ages in so far that violent storm-floods devastated 

 the coasts of the North Sea whereby the districts in which amber 

 was found: Friesland, the westcoast of Jutland and Schleswig, were 

 destroyed. I here recall the fact that there are statements in litera- 

 ture which connect the invasion by the Teutons and Cimbrians into 

 Gallia and later into Italy with a big inundation of the Sea 

 which destroyed their homesteads in Jutland (the Cimbrian 

 penninsula). 



These catastrophies, which probably began as early as the 6th 

 century b. C, struck directly the Scandinavian tribes who invaded 

 the German and later the Gallic countries. Italy first felt the shock 

 when the Gallic tribes began to raid the country. All the stages of 

 this transmigration of the northern tribes, which was the first to shake 

 the power of Rome, can now be traced thanks to the archseologic disco- 

 veries which were discussed by the archaeologic and geologic Con- 

 gresses at Stockholm 1908 and 1910. Kossinna of Berlin proved 

 that a transmigration of the tribes from the neighbourhood of the 

 Vistula began about 600 b. G. and Lienau of Limeburg traced the 

 same movement in the western provinces along the Weser. Next come 

 the proofs to be gathered from ancient writers of History (the ancient 

 Roman writers of History, Florus a. o.) who tell us of the Cimbrians 

 invading Gallia and Italy threatening the Roman republic by their 

 great victories at Noreia, where Papirius Carbo was defeated in 118 

 and at Arausio in 109, until Marius by his victory at Aquae Sextiae 

 averted the consequences of this first transmigration of the German 

 tribes from the countries on the Mediterranean. 



»Cimbri Teutoni atque Figurini ab extremis Gallice profugi cum 

 terras eorum inundasset oceanus novas sedes toto orbe qimrebant. » 2 

 This was the primary cause of the great transmigrations in the first 

 millenium b. C. which commenced with the decline of the Bronze-age- 

 civilisation through catastrophies in Nature which forced the inha- 

 bitants of the North Sea countries to emigrate. 



If we inquire into the physical causes of the alterations which 

 compelled the tribes of northern Europe to emigrate we find that 

 a maximum in the tidegenerating force of the sun and the moon 

 must have occurred about the 3rd and 4th century b. C. This caused 

 disturbances in the oceanic circulation such as storm-floods and in- 

 undations of the coast and a deterioration of the climate of the border- 

 land of the N. Sea and the Baltic. Its effect on the Atlantic coast 

 of Spitsbergen, Iceland and Greenland is traceable by the lowering 

 of the sea-temperature which caused the extermination of the delicate 

 southern species of molluscs, the Tapes, Anomia, Zirphsea a. o. Very 

 likely outbursts of polar ice also occurred as happened 18 centuries 

 later about 1300—1400 a. C. 



In the Littorina epoch there were oyster-beds along the coast 

 of Sjselland and the Scandinavian coast offered great opportunities 

 for the maintenance of a population both with regard to agriculture 

 and to fishery. The people of that time traded with the British Isles 

 as well as with the Mediterranean countries 1 . Besides fur and slaves, 

 amber was the chief article for barter. The supply of amber came 

 then chiefly from the North-Sea coast. The principal trade-route 

 was along the Elbe up to the Danube and then over the Brenner 

 pass into Italy. 



The climate at the culmination of the Littorina-epoch was At- 

 lantic, insular, but with the beginning of the great landelevation it 

 passed over into a warm and dry »sub-boreal» stage which lasted 

 the greater part of the Bronze-age up to 600 — 400 b. C. when the 

 climate deteriorated greatly and the civilisation of the Bronze-age 

 perished with the postglacial warm period. 



The land-elevation during the Littorina epoch was greatest on 

 the Bothnian coast. North of Hernosand it attained its^ maximum 

 of 288 meter. At Oresund and the Belts it was at its lowest, about 



5 — 6 meter, which however was sufficient to change the conditions 

 of the fish life in the Baltic in the manner already described. 



In the Bronze-age, 1600 — 650 b. C, the Scandinavian climate was 

 warm: all boundaries of vegetation in Sweden were then on the 

 average 3° further north than now. In proof of this B. Sernander 3 

 relates the following facts. 



In Sjselland millet was grown. Trapa natans, now extinct in 

 Sweden, grew in the lakes of northern Sweden. 



The hazel-tree grew in higher lat:s, and at greater height over 

 the sea in the Swedish Nordland. 



The boundary of the pine-forests lay in higher altitudes on the 

 mountain-slopes 4 . Stipa, now extinct safe in the neighbourhood of 

 Falkoping in Vestergothland, was then quite common. 



According to Sernander 5 the climate during the Bronze-age was 

 warm and dry. . The landelevation brought large areas, of the pre- 

 sent Baltic coast of Sweden, f. inst. part of Upland, above the sea- 

 level and numerous lakes and marshes were formed, which evaporated 

 in the dry climate. Sernander claims to have discovered a »drying 

 zone» in the bottom deposits of these lakes contrasting sharply with 

 the succeeding layers which consist of clay and sand brought thither 

 by the rivers during the next period which was markedly colder. 



We have of course no report as to the state of the Greenland 

 sea at this remote period, but we know something about the sea north 

 of Iceland from Pytheas journey in 330 b. C. He speaks of the sea 

 as »mare pigrum» a sluggish and congelated sea. It is curious that 

 ice and ice-hindrance are mentioned just then as being typical for the 

 northern seas and that 18 centuries afterwards, at the next maximum 

 epoch, the Icelandic annals also report new and powerful ice-blockades 

 of the coasts of Iceland and Greenland, whereas in the intervening 

 time in the 8th & 9th century a. C. the Vikings appear to have met 

 with no hindrance at all from ice in their journeys to Iceland, Green 

 land and America. Apparently a warm and ice-less period, which 

 favoured agriculture and shipping and allowed the Scan- 

 dinavian races to expand in the powerful manner which characterizes 

 the Viking-age, must have occurred between the interval of the two 

 maxima of 400 b. C. and 1400 a. C. This prosperous epoch then 

 corresponds to the former post-glacial heat-period or the Kjokken- 

 modding- and earliest stage of the Bronze-age 



The remembrance of the bygone civilisation two thousand years 

 earlier lived in the myths of the German race and found its expression 

 in the Edda. According to Victor Rydberg the myths of the Edda 

 centre around a great catastroph in Nature, the Fimbul- winter, 

 or »Gotterdammerung » when frost and snow ruled the world for 

 generations. 



One relict of the lost civilisation appears to have outlived the 

 »Fimbul-winter ». By the ancient temple of Upsala stood an enor- 

 mous tree, perennially green, which is thus described by Adam von 

 Bremen: »Prope illud templum est arbor maxima late ramos extendens 

 semper viridis in hieme et cestate, cujus ilia generis sit nemo scit. Ibi 

 etiam est fons ubi sacrificia paganorum solent exerceri et homo vivus 

 immergi. » 



Sven Nilson expressed the opinion that the holy tree of Upsala 

 was a yew-tree. Fritz Laffler in a recently published paper »Det 

 evigt gronskande tradet vid Upsala Hednatempel» (i Fastskrift till 

 H. F. Teilberg), has expressed the same opinion founded on a large 

 collection of proofs. Adam von Bremens statement: »no one knows 

 what kind of tree it is » has caused some difficulties because nowadays 

 the yew-tree can be grown in Upland and is still found in western 

 Norway although it requires a more temperate climate than ours. 

 In the Swedish museums also prehistoric vessels made of yew are 

 preserved. Conventz, who examined these finds, which belong to the 

 period 800 b. C. to 900 a. C, reports however, that vessels made of 

 this wood-material are very rare in the ancient provinces of Sweden. 

 This Schubeler corroborates. Nathorst reports that no fossil or sub- 

 fossil remains of the yew have been found within the precincts of 

 ancient Sweden. The vessel in the museum of Stockholm was found 

 in Bohuslan and the two vessels in the museum of Lund are probably 

 from Danish territory. Laffler says: »ancient Sweden would thus 

 be devoid of finds of antiquities made of the wood of the yew-tree. 

 This would sufficiently explain why the holy tree of ancient Upsala 

 was said to be of a kind unknown to the inhabitants of that place 

 in 1100 ». 



Laffler conies to the conclusion that during the Viking-age the 

 yew was extinct in Sweden, because it had been exterminated. He 

 believes, that the big tree at Upsala was a remnant left from a pre- 



1 O. Montelius: Handeln i forna dagar. Nordisk Tidskrift 1908. 



2 Florus III 3, 1. Ammianus Marcellinus (Leb XV, 9) speaks of the tradition amongst the Druids that their ancestors had been expulsed from the islands on the 

 other side of the Rhine by hostile tribes and by a great invasion of the .ocean. 



3 It. Sernander Postglaziale Klimaschwankungen im Skandinavischen Norden (Gerlands Beitrage zur Geophysik). 



4 Th. C. E. Fries Swedish Climate in the late-quaternary period XI Geolog. congress Stockholm 1910. 



5 Sernander. Sv. Bot. Tidskrift 1910. Bd. 4. 



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