92 



IOWA ACADEMY OF SCIENCES. 



In the subjoined table is given the average annual results 

 for each year from 1891 to 1902. 



YEARS 



NUMBER 



OF 



OBSERVING 



DAYS. 



AVERAGE ANNUAL NUMBER OF 



GROUPS. SPOTS. FACULAE 



TOTAL 



NUMBER OF 



SPOTLESS 



DAYS. 



PER CENT 



OF 



SPOTLESS 



DAYS. 



1891... 

 1892... 



1893.. 

 1894.. 

 1895.. 

 1896 . 

 1897.. 

 1898.. 

 1899.. 

 1900.. 

 1901.. 

 1902*. 



257 

 205 

 177 

 139 

 149 

 197 

 198 

 /34 

 259 

 255 

 269 

 220 



2.9 

 5.6 

 6.6 



.1 



.1 



.7 

 0.25 

 38 



24 



















5 



29 



30 



108 



134 



212 



156 



9 3 



0.0 



0.0 



GO 



0.0 



2.5 



14.6 



12.8 



41.7 



52.5 



78.8 



71 



*Not including month of December. 



Plate XXIV represents graphically the summaries of the 

 groups and spots, the former being indicated by the heavy, 

 smooth line, and the latter by the dotted one. 



In conclusion the author would state that the foregoing 

 brief and rather unsatisfactory review of the recent sun- 

 spot cycle was written rather hurriedly, but he trusts that 

 the account, as given, may not be uninteresting. 



All the observations were faithfully and accurately 

 made, and represent the conscientious labors of one who 

 has been occupied in an active business career and pursu- 

 ing other astronomical and meteorological studies as a 

 recreation. He is not unmindful of the many shortcom- 

 ings, and the difficulties involved in a discussion of the 

 results. 



List of the author's published sun-spot observations: 



189). September to December. — Mon. Rev. I. W. andC. S. 



1891. January to December. —Mon. Rev. I. W. and C. S. 



1892. January to December. — Mon. Rev. I. W. and C. S. 



1893. January to May. —Mon. Rev. I. W, and C. S. 



1894. May to December.— Mon. Rev. I. W. and C. S. 



189.5. January to June, A vi'^t to December. —Mon. Rev. I. W. and C. S. 



1895. Review Solar Observations, 1891 to 189.% (June).— Pub. A. S. P., Volume 8, No. 45. 

 189(5. January to December.— Mon. Rev. I. W. and C. S, 



1896. Review Solar Observations, 1895, (August to December), and 189(5.— Pub. A. S. P., 



Volume 9, No. t5. 



1898. Large Sun-spot of September. —P, A., Volume 6, No. 8. 



1899. Review Solar Observations, January to Aiigust.— P. A., Volume 7, No, 8. 

 1899. Review Solar Observations, September to December, P. A., Volume 8, No. 4. 



