122 
IOWA ACADEMY OF SCIENCE Voi.. XXVIII, 1921 
far the most interesting spots of the year were in September, when 
large and active ones were present and on the 25th remarkable 
electro-magnetic disturbances were reported in the daily papers as 
existing all over the United States and Great Britain, interrupting 
telegraphic and telephonic service. 
1910 
A marked decline in numbers of groups, spots and faculae was 
noted this year, and the number of spotless days greatly increased. 
The months of February, May, September and October recorded 
the latgest and most interesting groups, those of September and 
early October being of the train or stream character and of great 
extent. The closing two months of this year registered the least 
number of spots for a longer period than any other of the present 
cycle. 
1911 
The quiescent period noted above continued almost all of this 
year. At no time of observation, with one exception in April, 
were there more than two groups of spots present on the disc and 
all were relatively small, fully one-half the total number of days 
of observation revealing an absence of dark spots. 
1912 
During this year, as in the preceding one, the sun’s surface was 
very quiet, nearly three-fourths of the days being free of spots. The 
faculae also showed a marked diminution and the actual minimum 
of the cycle was near at hand. 
A few of the larger spots were traced during several rotations. 
That of March 8 reappeared early in April and was spectroscopic- 
ally active and increased to a considerable group. It reappeared for 
the third time early in May. A typical normal spot was present 
in June and some of the two-spot variety were present in October 
and December. 
1913 
This year undoubtedly marked the end of the minimum period, 
which must have been passed by the middle of the year, although 
it has been prolonged so much that it may be difficult to locate the 
period precisely. 
A small spot with outliers was seen in high north latitude about 
February 23, which may mark the beginning of the new cycle. 
Some dots also in the same latitude in July would indicate that the 
forces originating the new cycle of activity were already at work. 
Eighty-five per cent of the observing days were devoid of spots. 
