PROCEEDINGS. 
397 
between these and aurorae and terrestrial magnetism, and is prob¬ 
able between them and the temperature and pressure of the air 
and rainfall. Repeated attempts have been made to detect a 
variability in the solar radiation corresponding to the sunspot 
period, but unsuccessfully, because of the great and variable 
absorption by the earth’s atmosphere, and so observations at very 
high altitudes are needed. There is a probability that regions 
in the spectrum will be found for which the atmospheric absorp¬ 
tion is negligible or calculable. [Published in Monthly Weather 
Review, vol. xxx, p. 178 (1902).] 
Mr. Langley expressed his cordial approval of the statement 
of the problem just presented. 
Mr. C. Abbe then spoke on the General revision of Wolf’s 
tables of relative sunspot frequency, by Prof. A. Wolfer, of 
Zurich. Wolf’s tables, published in 1880, are the foundation of 
all attempts to prove coincidences. Wolfer has corrected many 
errors, and extended the tables from 1740 to date. It is note¬ 
worthy that the sunspots increase more rapidly than they de¬ 
crease. Prof. Newcomb’s results are not sensibly changed by 
the revision. There is no evidence in these figures for Lockyer’s 
35-year period. [Published in Monthly Weather Review, vol. 
xxx, p. 171 (1902).] 
In the following discussion Messrs. Abbot, Bigelow, Paul, 
Bauer, and Farquhar participated. 
554th Meeting. May 24, 1902. 
Vice-President Marvin in the chair. 
Thirty-one persons present. 
The election and qualification of Mr. A. F. Zahm was an¬ 
nounced. 
Mr. Bauer pointed out informally the remarkable magnetic 
activity at present, although this is near a sunspot minimum, 
and that effects at Cheltenham, in Kansas, and in Honolulu ap¬ 
pear to be simultaneous: magnetic disturbances have been noted 
synchronous with the Guatemalan earthquake of April 18 and 
the Martinique eruption of May 8. 
