Maunkiic 1)i.stli;ijan(:i: in tiik Suutu-Kast or Cait; Colony. 4r> 



declination observations. This is sliowii in fin', 'i. In it tiie lines f)f 

 equal (Jeelination are not slK)\vn, instead the declination has lieen com- 

 bined with the liorizontal intensity, and in that way the \alues of the 

 northerly and the westeilv intensitv have been dc'tei-niined. From 



She 



ma,aneli.iea ma-Utf 

 this mitt 



done I 



Ijic a.pproxima.U posdion of a.miss of 

 '.nil the pisdton a. miijnet a.dti} on by 

 aid like up it Vimaws pUeti /resrihos 



•«*, 



y 



Il ■ 



r 







ii.>.r/.>r... 



*Al..^^. •^*- 





The arrows sliow the direction in which a soutli pole Monid move in a 

 horizontal ])lane ; hence the ilotteil line f^ives the position of the south pole of 

 the jnacrnetised matter. 



these the mean values of the components have been subtracted, thereby 

 leaving the parts due to the presence of magnetised matter in the 

 district. 



It will be noticed that the position of the disturbing material 

 determined in this way is roughly along a line extending from the 

 south of Grahamstown westward to the north of Hankey. ^^'ere a 

 magnet acted on by this magnetisefi matter alone, and free from 

 the earth's mean effect, the .south pole would point awav from thi.s 

 line throughout its course. 



All three elements, therefore, unite in showing that in this 

 neighbourhood there is an intrusion of magnetised matter. It must, 

 Jiowever, be pointed out that the magnetic results tire not suthciently 

 accurate in their indications to show the exact position of this mag- 

 netic mass. They show unmistakably that there is in this neighbour- 

 hood such a mass; the position, however, cannot be "detei'mined to 

 within ten or fifteen miles, and though the position in fig. -5 is shown 

 as approximately a straight line, it must be lemembered that there 

 are not sutticient stations to justify this; the exact position t)f the line 

 could only be determined by further survey along with projier means- 

 for obtaining good values of the secular and the daily variations in 

 this part of tlse world." 



