— 237 — 



The star with foiir rays represents the Northpole, and 

 the aiTOws in direetion and length the horizontal vectors. 

 The values of tlie compoiients x^ and y^, as given by Lüdeling 

 in his quoted paper, have been used. 



The names of the stations, viz. Khujua Fjord. Godthaah, 

 Cape Thordseti, Jan Maijen , Bossehoi), Sodankt/ld, Novaja 

 Semlja, Ssagasttjr , Point Barroiv and Fort Bae have not been 

 inscribed in order not to confuse the aspect of the systom 

 of synchronous vectors corresponding to the 12 moments: 

 O'', 2'', 4'' 22'' mean time of Göttingen. 



On each of the 12 maps it is more or less obvious, how 

 one part of the vectors poiut towards a focus, and the other 

 part point away from another focus. 



Especially for the vectors of the neighbouring- stations: Cape 

 lliordsen. Jan Manen, Bossekop, Sodanki/ld and Novaja Seinlja 

 for some hours, as C', 12'', 14'\ 22'', this is very striking. 



On each map the place of these foei has been indicated by 

 a little circle in which a + or — sigu has been inscribed ; the 

 + sign for the focus towards which vectors point, the — sign 

 for the one from which they liy. As there is a strong personal 

 element in the choice of these places, the maps have been 

 reproduced here open to the criticism of the reader. 



To do away with any prejudice as much as possible in the 

 choice, it has been done designedly without taking notice 

 of the hour for which the map had been constructed, and 

 afterwards the places selected have not l)een altered. 



For the determination of these places a rectangular system of 

 coördinates, with their origin in the Northpole, has been used- 

 For the + x axis and + y axis respectively the meridians 

 of 180" and '.)0" W from Creenirich have been taken. For 

 unit of length 2tg0''.5 has been chosen, because the maps 

 have been drawn in stereographic projection from the 

 Southpole; accordingly y^'^x^ = tg p, p being the polar 

 distance expressed in degrees. As p is small for most arctic 

 stations, we may take p for tg p, and consequently consider 

 one degree as unit of length. 



