Eclipses 



supplied evidence of a periodic law which 

 remains entirely unexplained, though it is un- 

 mistakable. Every eleven years, roughly, the 

 activity of the sun reaches a maximum. Now 

 the eclipse of 1900 took place during a period 

 of quiescence; 1905, on the contrary, was a 

 year of great agitation, and consequently all the 

 phenomena connected with this increased solar 

 perturbation, such as the protuberances and the 

 development of the gaseous corona, were expected 

 to be present in especially favourable conditions 

 for examination. All these details show that 

 each eclipse has a special physiognomy of its 

 own, and facilitates in greater or less degree the 

 solution of the many solar problems. 



Many have been the descriptions of the 

 striking appearance presented by Nature 

 during a total eclipse of the sun; but we shall 

 mention here only the facts suitable for scientific 

 study. 



A few seconds before totality the visible 

 part of the sun forms a crescent, which decreases 

 with surprising rapidity ; it is soon reduced to a 



mere thread, split into separate lengths by the 



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