No. 7.] HORIZONTAL INTENSITY. 69 
DETERMINATION OF THE CONSTANTS. 
DIRECT DETERMINATIONS. 
The constants employed in the calculation of the horizontal intensity, 
according to the formule given on page 64, are the temperature coefficient c, 
and the quantities C and wu. 
These constants, as already mentioned, were determined by observations 
in Hamburg, between the 3rd and the 9th June, 1893, with the following 
results, given in Dr. NeuMayErR’s manuscript: 
Hamburg 
1893 
0-11769 | 0076812 
0-11799 | 0-076668 
0-11831 | 0076921 
0:11799 | 0:076800 
0°14628 | 0095074 
0-14616 | 0095178 
0-14658 | 0:095456 
0°14634 | 0:095934 
0:27245 | 0°17735 | 0°000307 
0:22169 | 0:000638 (?) 
In order in the first place to get an idea as to how the constants C 
and w had remained during the expedition, I first deduced their value from 
the complete series of observations taken after the return in Wilhelmshaven, 
in April, 1897, employing the value of the temperature coefficient «, found 
in Hamburg in 1893, as no later direct determination of it has been made. 
The calculations gave the following result: 
Wilhelms- 
haven 
1897 
April 18 0°11761 | 0°076503] 0:27148 | 017658 
— 19 0:11753 | 0:076366] 0°27157 | 0:17644 
Mean 011757 | 0°076435] 0°27153 0°17651 
April 18 0714227 | 0092520] 0:34006 | 0:22116 
— 19 0°14218 | 0:092520 | 034020 | 0°22159 
| 
Mean 0:14223 | 0:092520] 034013 | 0:22128 
