1889.] THE DISPLACEMENT OF BEACH-LINES. 7 



strata occur in each stage. The entire Oligocene epoch contains 

 only about 30, the Miocene still fewer, and the Pliocene scarcely 

 20 such alternations of strata. 



In this manner precession has, in my opinion, left its im- 

 prints on the strata, and these should thus become a means of 

 measuring geological time. The greater the eccentricity of the 

 Earth's orbit has been, the more distinct will the traces of the 

 period be; when the path approached the circular form the traces 

 of the period will become less distinct. 1 



Whilst I refer my readers to the Memoirs already named, 

 and to my Paper on „Variations of Climate in the course of 

 Time" (Letterstedtske Nordisk Tidsskrift 1885 in English, in 

 Chria. Vid. Selsk. Forh. 1886 No. 8 and „Nature", London 8 and 

 15 July 1886), I will pass on to examine whether there is any rea- 

 sonable ground for assuming that also the second supposition is 

 correct; whether it is possible that the level of the seas rises 

 and falls in higher latitudes with the eccentricity of the 

 Earth's orbit. 



Large portions of the Earth's surface consist of layers which 

 still lie undisturbed in their original level position. These por- 

 tions Suess has called tables. But in many parts the terrestrial 

 crust is so cut up by cracks and fissures that it may be likened 

 to a breccia. The broken parts are often displaced, in relation 

 to each other, thousands of feet, Beds which originally lay 



which has also left traces in other places on our hemisphere, was, in ray 

 opinion, the consequence of an unusually long period of winter in aphelion. 

 The winter solstice occurred in aphelion (cfr. Croll), 61,300, 33,300 and 

 11,700 years ago. The middle of the Atlantic period, with Bergen marine 



mosses, 33-34,000 years ago, consequently subsequent to the 28,000 year 



