252 DETERMINATION OF THE ELEMENTS OF TERRESTRIAL 



Greely as observed at Lady Franklin Bay, 1882. A serious 

 effect of these magnetic storms is alluded to in a recent paper 

 by Sir Norman Lockyer, who says, speaking of ' the well 

 marked coincidence ' between the variation of magnetic effects 

 and the quantity of spotted area on the sun, "This in later 

 telegraphic days is not merely a pious opinion which does not 

 interest anybody, because when the magnetic changes are very 

 considerable, and the disturbances arrive at a maximum, it is 

 very difficult to get a telegram from London to Brighton." *^^ 

 During the great magnetic storm of Oct. 31, 1903, telegraphic 

 connnunication in Spain was interrupted from morning till 

 midnight. At 3 hrs. 20 min. the cable from Cadiz to Teneriffe 

 was so perturbed that the clerks grounded it to avoid the dis- 

 charge. This storm at Falmouth, England, was also of excep- 

 tional violence, the declination magnet there swinging through 

 an arc of 2^ 2'. That there is a connection between disturb- 

 ances on the sun and magnetic storms is undoubted, but Lord 

 Kelvin, reasoning from the immense amount of electrical 

 energy which the sun would have to give out if it alone were 

 the cause of these disturbances, concludes that great magnetic 

 storms cannot be due entirely to the direct action of the sun. 



" The probability is that a solar ray endowed with greater 

 or less energy than ordinarily and of the necessary kind acted 

 as the ' trigger to the gun ' to set off mighty electric forces 

 whose presence in the upper regions is becoming more and more 

 manifest every day."*^* Some of the effects of this solar influ- 

 ence have been noted, it is thought, during total eclipses. Dur- 

 ing the eclipse of May 28, 1900, members of the LT. S. Coast 

 and Geodetic Survey noticed a slight magnetic effect which 

 might be attributed in some way to the changes produced in the 

 upper atmosphere when it was shielded from the sun's rays. 

 To try to settle this question, an extensive series of observations 

 were made during the eclipse of May 17, 18, 1901. The obser- 



(1) Paper presented to the International Meteorological Committee at Southport, 

 Sept. 11, 19(J3, by Sir Norman Lockyer, K. C. B. 



(2) U. S. Declination Tables for 1902. L. A. Bauer, p. 56. 



