ON “QUIET” DAYS DURING THE ELEVEN YEARS 1890 TO 1900, ETC. ;U):i 
Table IX.—Non-cyclic Effect. 
Year. 
Declinatiou. 
Number of months. 
Inclination. 
Number of months. 
Horizontal force. 
Number of months. 
Vertical force. 
Number of months. 
4- 
0 
- 
-9 
0 
- 
-1- 
0 
- 
4- 
0 
- 
1890 . . . 
1 
1 
10 
3 
1 
6 
9 
1 
2 
4 
1 
5 
1891 . . . 
11 
0 
1 
1 
0 
11 
8 
3 
1 
6 
0 
6 
1892 . . . 
s 
1 
o 
O 
0 
1 
11 
11 
1 
0 
5 
0 
7 
1893 . . . 
4 
2 
6 
0 
3 
9 
11 
1 
0 
3 
1 
8 
1894 . . . 
7 
1 
4 
3 
2 
7 
10 
1 
1 
5 
1 
6 
1895 . . . 
4 
1 
7 
0 
w 
1 
9 
11 
0 
1 
2 
0 
10 
1896 . . . 
5 
1 
6 
1 
3 
8 
10 
2 
0 
6 
1 
5 
1897 . . . 
5 
1 
6 
0 
1 
11 
12 
0 
0 
5 
2 
5 
1898 . . . 
5 
2 
5 
0 
2 
10 
11 
0 
1 
4 
2 
6 
1899 . . . 
7 
2 
3 
0 
0 
12 
12 
0 
0 
2 
0 
10 
1900 . . . 
6 
2 
4 
3 
2 
7 
7 
2 
3 
5 
1 
6 
Totals. 
63 
14 
55 
13 
16 
101 
112 
11 
9 
47 
9 
74 
Table X.—Non-cycllc Effect, Seasonal Values (Means from 11 Years). Unit = ly 
in case of Force. 
1). 
w. 
H. 
N. 
1 . 
V. 
T. 
Winter. . . . 
4-o'-134 
4-1-72 
4-3-50 
4-3-13 
-0-252 
-0-68 
4-0-72 
Equinox . . . 
4-0-068 
4-1-44 
4-3-66 
4-3-39 
- 0 - 254 
-0-46 
4-0-99 
Summer . 
-0-070 
4-0-50 
4 -2-86 
4-2-84 
- 0 - 2.30 
- 1-39 
-0-18 
Year .... 
4-0-044 
4-1-22 
4-3-34 
-f 3-12 
-0-245 
-0-84 
4-0-51 
§ 15. The declination (see Talile V.) is the element in whicli the non-cyclic effect is 
smallest and most variable in smn. The D curves are read only to the nearest O'd, 
so that apparent non-cyclic changes of this amount on mdivulual days j^ossess little, 
if any, significance. If we take the last six years in Table V., we see that the mean 
non-cyclic effect for the year in no case exceeds O^'Oo, and if we comhine these six 
years, we obtain a mean non-cyclic effect ^y]llch absolutely yanishes. Again, while 
the mean non-cycllc effects for 1890 and 1891 are of substantial size, they are opposite 
in sli>:n. 
o 
d'hese facts are certainly calculated to rouse suspicions as to the bond fide nature of 
the non-cyclic effect in 1). Tliere are, lioweyer, a yariety of considerations which 
point to its having a real physical origin. 
In the first place, the contribution of the true secular change to the mean non-cyclic 
effect in D, yiz., “ 0'‘01G, is in the opposite direction to the resultant effect, so that 
yOL. CCIL—A. 2 z 
