26o IKIDIJOF NANSKN. M.-N. Kl, 



rro\i'lc'l lliat llic iiplicaval of the laii'l lias increased rej^ularly in- 

 laii'l, ami pro\ iflcd tlial llic relation between the inclinations of the two 

 planes of the shore lines has been similar to what is represented in Fig. 167, 

 llu-n we should be able to conipule ilie probable height of the Tapes level 

 at anv place where we know the upiur linnt of submergence. 



l)Ctween llelgoi and llavnnes (I'ig. 167) the upper limit of sub- 

 mergence rose 43.9 metres (from 17 metres to 60.9 metres), while the 

 Tapes-line rose 13.5 metres (from 9.3 metres to 22.8 metres). Hence, 

 for every metre whicli the u[)per limit of submergence rises landwards 

 the Tapes-line will rise 0.308 metre. If .r be the lieight above the sea 

 of the ]>oint, where the planes of the u])per limit of submergence and of 

 the Tapes-line intersect one another, and // be the height of the upper 

 limit of submergence above sea-level, the height // of the Tapes-line will.be: 

 // = (//— .V) -• 0.308 + X 



According to the above values of // anrl /; on Helgoi and at Havnnes 

 .r is = 5.87 metres. Hence: 



// = {H — 5.87 )>< 0.308 + 5.87 



// = //X0.3 + 4 (i) 



By taking tlie mean of Hclland's measurements of both shore-lines 

 at six places where the height of the upper shore-line was between 57 

 and 62.7 metres and at seven places where it was between 28.7 and 38.4 

 metres we find the formula to be: 



/i = //X0.315 + 3.4 I2) 



The values computed by this formula docs not differ much from 

 those comj^uted bv the former formula. 



In order to test the correctness of our formula let us take some 

 reliable observations of the upper marine limit and the Tapes-level in a 

 region as far away from the Tromso district as the Christiania valley. 



At Skådalen Station, on the Holmenkollen tramway, near Christiania, 

 P. A. Öyen has found the upper limit of submergence at a height of 220.8 

 metres above sea-level. At Cllern, west of Christiania, he found the 

 Tapes-level at a height of 69.5 metres. The distance between Skådalen 

 and Ullern is about 4 kik^metres at right angles to the probable direction 

 of the isobases in this region. If we assume the gradient of elevation 

 to be about 0.7 per mille, the height of the upper limit of sul)mergence 

 at Ullern should consequently be 218 metres. Hence the height of the 

 Tapes-level at Ullern should be: 



h = 218x0.3 + 4 = 69.4 metres 

 or 



/i = 2i8-^^<o.3i5 -|- 3.4 = 71.3 metres. 



This agrees well with ()ycn"s value, O9.5 metres, especially con- 

 sidering that our formula is based only on some few observations by 

 Heiland in the Tromso district. 



