1898-1902. No. 6.] TERRESTRIAL MAGNETISM. 63 



SUMMARY OF THE RESULTS. 



In the following table of the values of H, deduced separately from 

 vibrations and from deflections, and expressed in y [y = 0.00001 c. g. s.), 

 it will be seen that there are several considerable discrepancies between 

 the two. This is also natural enough when the various circumstances 

 that may have influenced the accuracy of the results calculated, are 

 taken into consideration. 



Among these may be mentioned 



(1) The inconstant magnetic conditions peculiar to the regions sur- 

 rounding the magnetic pole, of which, owing to the want of variation 

 instruments, it was impossible to take account. 



(2) The effect of the daily range of the horizontal intensity, which in 

 these regions in the summer may be assumed to be very con- 

 siderable. 



(3) The unsatisfactory conditions of temperature prevailing while the 

 observations were being made. 



(4) The absence of determinations of the torsion of the suspension 

 thread during the vibration observations. This want makes itself 

 especially felt in the regions about the magnetic pole, where the 

 directing force of the vibration magnet is so small. 



(5) The somewhat considerable changes that are proved to have taken 

 place in the magnetic moment of the two deflectors during the Ex- 

 pedition. 



Although there is certainly every reason to assume that the deflec- 

 tion observations made in high magnetic latitudes give more reliable 

 values for the horizontal intensity than the vibration obervations, yet, 

 in consideration of the far larger number of the latter in the present in- 

 stance, I have calculated the mean value of H for every day of obser- 

 vation according to the formula 



Hv-\- Hj) 



H- 



2 



where Hy and Ho are the mean of all the single values of the hori- 

 zontal intensity found that day by respectively vibration and deflection 

 observations. 



The final value of H will then be the mean of the values that 

 magnets V and VI give, if both magnets have been used on the 

 same day. 



