522 



REPORT 1867. 



Deferminafions of Horizontal Magnetic Intensiti/. 



The equivalent deduced from the third series is therefore 



X -3.5478 X 32465480 x 3600 



(-62723 op—? 

 16:2832 ^^•^^'' M- 



:2521^ 



30-5821 

 124)5f^^^'^^'^ 



The cquivalent.s above arrived at are : — - 



From Series 1. Average of 10, 25335, 



From Scries 2. Average of 15, 25366. 



From Series 3. Average of 30, 25217. 

 The extra precautions taken in the last Scries entitle the last figure to 

 be taken as the result of the inquiry. Reduced to -sveighings in vacuo it 4 

 becomes 25187. ' 



