18 
IOWA ACADEMY OF SCIENCE 
The following tables exhibit the numerical results of the observations front! 
1891 to 1907, inclusive: 
Years 
No. of days 
observa- 
tions 
Average 
groups 
Annual spots 
Number of 
faculae 
Total No. of 
spotless 
days 
1891 
257 
2.9 
14.9 
3.6 
24 
J89a 
205 
5.6 
34.0 
4.1 
0 
1893 
177 
6.6 
36.6 
4.1 
0 
1894 
139 
5.6 
30.0 
3.4 
0 
1895 
149 
5.2 
30.5 
3.5 
0 
1896 
197 
3.2 
17.8 
2.9 
5 
1897 
198 
2.2 
11.0 
2.3 
29 
1898 
231 
2.1 
11.0 
2.4 
30 
1899 
259 
1.1 
4.8 
1.5 
108 
1900 
255 
0.7 
3.4 
1.0 
134 
1901 - 
269 
0.25 
0.9 
0.3 
212 
1902 
230 
0.37 
2.0 
0.5 
163 
1903 
230 
1.65 
7.8 
1.9 
32 
1904 
172 
3.10 
13.25 
3.14 
0 
1905 __ 
202 
4.00 
18.18 
3.9 
2 
1906 . 
198 
3.8 
15.0 
3.3 
8 
1907 
205 
3.8 
15.8 
3.4 
0 
The maximum and minimum daily number of sun-spot groups are given im 
the table below: 
MAXIMUM DAILY NUMBER OF SUN-SPOT GROUPS 
Months 
1903 
1904 
1905 
1906 
1907 
January 
1 
4 
6 
. 7 
7 
February 
3 
3 
8 
4 
9 
March 
3 
5 
6 
7 
7 
April 
5 
4 
5 
9 
6 
May 
4 
6 
6 
6 
4 
June 
3 
5 
6 
10 
3 
July 
4 
5 
6 
10 
5 
August _ 
3 
5 
7 
6 
6 
September 
2 
3 
6 
7 
8 
October 
3 
5 
7 
3 
7 
November 
4 
6 
8 
6 
5 
December ♦ 
6 
9 
5 
6 
4 
MINIMUM DAILY NUMBER OF SUN-SPOT GROUPS 
Months 
1903 
1904 
1905 
1906 
1907 
January 
0 
1 
1 
1 
4 
February — 
0 
1 
2 
2 
5 
March 
0 
2 
2 
1 
2 
April 
0 
1 
1 
1 
1 
May _ 
0 
2 
0 
2 
1 
June 
0 
2 
2 
1 
1 
July 
0 
1 
1 
4 
1 
August 
1 
2 
3 
1 
2 
September 
0 
1 
1 
1 
3 
October 
1 
2 
2 
0 
2 
November 
1 
1 
2 
1 
1 
December 
0 
2 
2 
4 
1 
