vious period, »It cannot be denied, that such a tree may have grOwn 

 from a seed brought from abroad, or that the population may have 

 protected and guarded this relict of a past vegetation. » 



In this conjecture Laffler is probably right. The yew-tree grows 

 very slowly and may certainly attain an .age of 1000 — 2000 years. 

 We have every reason to believe that the holy tree of Upsala was 

 more than 1000 years old and had survived from the Bronze-age. 



Great transmigrations af people occurred also in the second mil- 

 lenium b. G. Then too the direction of the movement was towards 

 the Mediterranean countries and it is not impossible that its cause 

 may also have been unfavourable climatic conditions in northern 

 Europe, which, according to our theory, should have culminated 

 about 2000 b. G. It should also be remembered that at the time of 

 the melting of the inland-ice in Sweden, cold and warm periods must 

 have alternated. 1 The traces left in the stratified clays indicate 

 that the melting process was not uniform the whole time through. 

 It would be of great interest to ascertain whether some kind of 

 periodicity can be traced in the ice-melting process. 



Going back so far as to the melting of the ice-cover or about 9000 

 years ago we have to take into account one more fact, i. e. the change 

 in the excentricity of the ecliptic and in the inclination of the earths 

 axis against the ecliptic, which according to Ekholm and Charlier 

 must have caused a warm period about 9000 years ago (and a cold 

 period about 28000 years ago). 



If we keep to the theory that climatic variations are caused by 

 cosmic agents, then we must conclude that the greater variations 

 which accompany the geological epochs (the glacial period, the ter- 

 tiary period a. s. o.) are ruled by changes in the ecliptic and in the 

 position of the earth's axis and the lesser variations, which are the 

 subject of this investigation, are ruled by changes in the position of 

 the orbit of the moon of which the longest periods encompass some 

 18 centuries with minor periods of 93, 18, 9, 4% years a. s. o., the 

 briefest, or those which influence the - weather, measuring months 

 or weeks. 



Several maxima of the tide-generating force have fallen in the 



interval between the melting of the inland-ice and the end of the 

 Littorina-epoch. These maxima have been accompanied by cata- 

 strophs in Nature such as storm-floods, inundations a. s. o. On 

 the coast of Scania there are remnants of such catastrophs in the 

 shape of shingle-banks, as e. g. the »Jarabacken» which must 

 have been formed in prehistoric time. It would be interesting to 

 find out if its formation coincided wit the critical epochs of the Stone- 

 age and the Bronze-age here described. 



Sven Nilson held that Jarabacken was formed by a violent up- 

 roar of the sea probably at the end of the Bronze-age, which event 

 marked the time of the great emigration of the northern tribes 600 — 

 100 b. C. Recent geologic and archaeologic investigations make it 

 probable that Jarabacken belongs to an earlier period. De Geer 

 who has traced this formation all round the coast of Scania beleives 

 that it marks the maximum limit of the sea during the Stone-age. 



It is a recognized fact that after the glacial period great variations 

 of climate have occurred. My effort has been to show in this paper 

 that these climatic variations are connected with variations of the 

 tide-generating force. At the epochs when maxima in the tide-gene- 

 rating force occur, changes in the climate Lave occurred which in 

 some cases have assumed a catastrophic character whereas at the 

 time of minima the climatic conditions appear to have been more 

 stable and uniform. I have shown that there is an interval of about 

 18 centuries between the absolute maxima, the last one occurred at 

 the end of the Middle-ages and the last minimum at the beginning 

 of the Viking-age. The diagrams on page 7 show the position of the 

 lunar orbit in 1434, 1894, 1903 and in 1912. The diagrams show 

 clearly the difference between our time and the time of absolute 

 maximum 500 years ago. It is also evident that a secondary maxi- 

 mum of the type we call perihelion-apside has approximately occurred 

 within the last 18 years at the time of the wintersolstice and the 

 earths perihelion. 



These constellations have shown their effects in certain changes 

 of short period in the climate, but chiefly in disturbances of the ice- 

 conditions in the arctic and antarctic seas and the polar currents. 



1 At least three such alternations can with surety be traced in the clay deposits examined by de Geer and his disciples and there are probably still more to discover. 



Wald. Zachrissons Boktryckeri A. B., G-oteborg 1914 



