776 



3Ir. Charles Ghree 



[March 4, 



much larger than the winter vahie of the inequahty range. If the 

 days of large disturbance, averaging 11) a year, had been included in 

 Taljle III., the pre-eminence of the equinoctial value of the absolute 

 range would have been greater. In the present case, it should be 

 added, Kew is fairly representative of all stations in temperate lati- 

 tudes. 



§ 7. When we pass to days of large disturbance, the prominence 

 of the equinoctial season in temperate latitudes becomes accentuated. 

 This is shown by Table IV., which gives the seasonal distril)ution of 

 the 721 magnetic storms recorded at Greenwich from 184(S to 190o, 

 as calculated from the lists drawn up by Mr. W. Ellis and Mr. E. AV. 

 Maunder, with corresponding results for Batavia from 1883 to 181)9, 

 obtained by Dr. Van Bemmelen. 



Table IV. — Seasonal Distribution of Magnetic Storms. 



riacc. 



Greenwich 

 Batavia 



Epoch. 



1848-1903 



1883-1890 



I'ercentagc of all Recorded. 

 Winter. j Equinox. Summer. 



32 

 33 



L9 



35 



26 



32 



Out of every 100 storms recorded at Greenwich, 42 occurred in 

 the 4 equinoctial months ; the number in summer was less than the 

 numl)er in winter. 



The seasonal variation seems to diminish as we approach the mag- 

 netic e(|uator, and ])ut little remains of it at Batavia. 



§ 8. When we pass to high latitudes the pre-eminence of the ecjuiiiox 

 as a season for magnetic storms seems to disappear entirely. This is 

 shown by Table V., which compares declination results at Kew and 

 at the ' Discovery's ' winter quarters. 



Table V. — Percentage of Days having Range over 20' at Kew, and 



OVER 120' AT THE ' DISCOVERY'S ' WiNTER QUARTERS (77^ 51' S.). 



At Kew, out of every 100 days at midsummer (May to July), 

 only U had an absolute range over 20', the corresponding figure for 



