210 
PROFESSOR KEELY’S MAGNETICAL OBSERVATIONS. 
These observations gave for the mean value of log h, ‘3377587, at a mean tempera- 
ture of 58°‘2, and hence log '7r‘^k = r3320584. If this value of is reduced to 
the temperature of 63°-3, by the formula 1 -f2e(^'— ^), it gives 1-3320885, differing 
from the former observed value only -0000038. Where in the table three observa- 
tions are included in one set, the mean of the true corrected values of T for the first 
and third was taken and combined with T', so as in some degree to eliminate changes 
of force. 
Table VIII. contains the uncorrected particulars of my observations of vibrations 
and deflections at Halifax, Annapolis and Fredericton, and those of vibration only 
at Kentville ; with the nearest observations, before and after my tour, at Water- 
ville. 
Table IX. contains m, X, and the total force ; a mean for the value of m at Kent- 
ville having been taken from the values at Halifax and Annapolis. 
Table X. contains the total forces at the four stations obtained by the unifilar 
reduced to Waterville by the observations of the Lloyd needle L(I) at the same 
stations, in order to test the accuracy of the observations ; an additional column 
shows the same comparison for the only two stations where the two Lloyd needles 
and unifilar were all used ; in other words, having obtained the total force at, say, 
Halifax by the unifilar, and also the relative force by the Lloyd needles, and know- 
ing also the relative force at Waterville by the Lloyd needles, and therefore the ratio 
of the force at Halifax to the force at Waterville by the Lloyd needles, I multiply 
the aforesaid total force at Halifax got by the unifilar by this ratio, and obtain the 
total unifilar force at Waterville, and so with the rest. 
Table VIII. 
Station. 
Date. 
Magnet. 
U. 
Tempe- 
rature. 
u'. 
Tempe- 
rature. 
Time of 
one vibra- 
tion. 
Number 
of vibra- 
tions. 
Tempe- 
rature. 
Com- 
mencing 
arc. 
Final 
arc. 
Rate of 
chron. 
Torsion for 
90° in sc. 
divisions. 
4 28-5 
Sc. div. 
Sc. div. 
Waterville ... 
July 29. 
H(10) 
12 2i-3 
6,3-8 
64-1 
4-35021 
548 
66-4 
6-5 
1-1 
■8925 
30. 
HflO) 
12 21-6 
67-6 
4-35277 
460 
72-0 
5-25 
0-75 
1-009 
Halifax 
Aug. 21. 
11(10) 
4 26 
64-9 
4-34901 
338 
71-5 
5-0 
1-0 
-8-5 
•69 
Kentville 
24. 
1-1(10) 
4-36005 
238 
61-9 
5-0 
1-0 
-8-5 
-6018 
Annapolis ... 
27. 
HGO) 
4 26-2 
65-0 
4-35008 
344 
68-5 
5-5 
0-8 
-8-0 
•52 
Freflpirieton . . 
HHO) 
4 49 
71-2 
4-53733 
344 
72-5 
4-9 
0-7 
-7-0 
•7225 
Waterville ... 
25. 
H(10) 
12 10-9 
61 
4 24-9 
60-4 
4-37520 
356 
56-0 
8-4 
1-4 
-6-2 
1-01 
In this Table u and v! are given to the nearest tenth of a minute, but in the cal- 
culations the value in seconds was employed. 
