AMERICAN ALMS FOR BRITISH SCIENCE. 93 



on eclipse after eclipse, in former times, without adding 

 jot or tittle to our knowledge of solar physics. But 

 during recent eclipses things have altered. In 1860 

 the celebrated ' Himalaya Expedition ' sailed to Spain 

 from England ; while other parties came from France, 

 Italy, and Germany. And though the old fault of 

 wasting observing energy on matters already known 

 or demonstrated prevailed very largely, yet De la Rue 

 and Secchi, by photographing the eclipsed sun, well 

 repaid the whole cost of these expeditions. In the 

 great total eclipse of August 1868, Europe sent out 

 many observing parties to India, and the great dis- 

 covery that the red prominences seen round the totally 

 eclipsed sun are masses of glowing vapour sufficiently 

 repaid the cost. In August 1869, the Americans 

 availed themselves right skilfully and worthily of the 

 passage of the moon's shadow across their continent ; 

 and though they failed in the main purpose they had 

 set themselves, they made preliminary observations of 

 the utmost importance and value. That purpose was 

 to ascertain the nature of the glorious aureole of light 

 seen around the sun during total eclipses ; and it is 

 with the same purpose that the expeditions formed for 

 observing the present eclipse were to have set forth. 

 The questions to be answered are full of interest, even 

 now when their full significance is not known ; while it 

 may well be that when we begin to have accurate in- 

 formation about them, we shall find they have a real 

 importance wholly unlocked for. As the last direct 

 rays of the sun are concealed by the advancing moon, 



