MAGNETIC INCLINATION AT GOTTINGEN. 653 
Observations with Needle 4. 
rd “ “/ 
June 8. | A | 6745 9 | 6727 3 | 5:96200 
9. | B 2256 | 68 828 | 5-91653 
11. | B 23 16 748 | 5:94665 
Wai hethe 4954 | 6712 8 | 601785 
1s. | B 27 48 | 68 845 | 5:93204 
22. | B 26 46 356 | 594065 
93. | A 5019 | 671537 | 5-93939 
25. | A 50 4 15 22 | 5-94731 
July 17. | A 50 13 15 43 | 596850 
is.) a 49 57 14 48 | 596931 
1922p 22 43 | 68 918 | 5-92673 
20. | B 22 41 10 19 | 592783 
24, 
In the calculation of these observations, instead of ¢, u em- 
ployed above (Art. 21, 22), I shall introduce somewhat modified 
auxiliary quantities. If for one of the needles we denote by » 
the time of a horizontal vibration, by # the sum of the mo- 
ments of inertia of the needle and of the stirrup in relation to 
the axis of rotation, which in these observations is vertical, and 
by 7 the length of the second’s pendulum, then it is known that 
lmn? cosi=k. 
Let us select a normal time of vibration N and a normal incli- 
nation I, being about the mean of the values of ” and i, and let 
M denote the corresponding value of m, so that 
IM N? cosIl =k. 
Lastly, let 
ao = £098 Q.cos I . 206265" 
my M 
g sin Q. sin I . 206265" 
DS Gis eas OF eee 
which quantities are constant for all the observations with this 
needle. The equations then become 
Pe fet n> cos f cost n? sin f cost 
N?cos 1° cos 1° NsinI * cos’ 4% 
n? cosg cos it n? sing cosi 
*=9— °—~ NicosI ‘ cosl’” — N?sinI* cosl'? 
if B is a north pole; for the case of A a north pole, it is only 
necessary to give the contrary signs to the members which con- 
tain v and y. 
