No. 7.] HORIZONTAL INTENSITY. 75 
not give sufficiently serviceable material for investigation. For the cases in 
which magnet VJ has been used, therefore, I have simply had to take the 
value found in Hamburg in 1893 for the temperature-coefficient: 
a = 00006838 . 
THE FINAL VALUES OF THE CONSTANTS « AND C. 
The assumption that the magnetic moment of magnet V, and thus the 
factor « also, have remained constant throughout the expedition, is made, as 
already mentioned, the basis of the final calculation of the temperature- 
coefficient of the magnet. As a check on the correctness of this assumption, 
I have again calculated « with the final value of « for each of the 8 certain 
normal days with the following result: 
1894. Dee. 7 0.076127 
1895. May 24 0:075995 
Ocia 17 0°11615 0°075996 
Dec. 12 0076094 
1896. Jan. 28 0°076105 
0°11619 0:076048 
0°11620 0:076100 
0°11622 0°075952 
0°11619 0°076052 | 
The values found agree, as the table shows, very well with one another, 
March 19 
1897. April 17 
=a 
Mean 
and I have therefore assumed the mean of all the determinations as the 
final value of w for the respective distances e and EF. 
No observations permitting of the determination of « were made with 
the small declination-needle as deflected magnet during the expedition. For 
this mounting of the apparatus, I have therefore kept to the determinations 
in Hamburg in 1893, and in Wilhelmshaven in 1897. I have recalculated 
the latter, introducing the improved ultimate value of «@ and obtained: 
