1906.] 0)1 Eclipse Problems and Observations. 237 



rarefied vapours ; and then we have these magnetic storms on earth 

 possibly arising from some influence coming out from the sun. 



I turn now to the observations which have been made during the 

 last echpse, August 80, 1905, and shall confine myself to those 

 expeditions which were sent out by the Royal Society and the Royal 

 Astronomical Society. Seven expeditions were organised under the 

 auspices of their joint Committee, and seven stations were occupied 

 along the track of the shadow of the moon. 



Many of these expeditions were helped by appropriations from 

 the Grovernment grant administered by the Royal Society, and also in 

 a very marked way by the kind assistance of a number of volunteer 

 observers. 



The track of the moon's shadow passed through Labrador, and 

 there Mr. Maunder was stationed, hoping to get observations at the 

 beginning of the track of the eclipse which would be comparable 

 with the observations got at the last station on the eclipse line by 

 Professor Turner, at Assuan. Unfortunately, the weather conditions 

 w^ere bad in Labrador, and the observations were, therefore, frustrated. 

 Then the shadow track passed across the Atlantic, and arrived on the 

 coast of Spain. Two of the parties to which I have refen'ed were 

 stationed in Spain. One, that of Mr. Evershed, was stationed at 

 Pineda de la Sierra, between Burgos and Bilboa ; the other, that of 

 Professor Callendar and Professor Fowler, was at Castellon de la 

 Plana. Mr. Evershed was stationed at an altitude of about 4000 feet 

 in the mountains ; and Mr. Callendar and Mr. Fowler were stationed 

 near the sea coast. Both parties were very hardly treated by the 

 clouds, for, in spite of the careful preparations which had been made 

 for the purpose of the observations, no observations could be made. 

 It is difficult to convey the disappointment which this means, not 

 only to those who suffered the actual distress of finding all their 

 preparations frustrated, but also to those who hoped that records 

 would be got for study and for comparison with results got in other places. 



Sir Norman Lockyer, accompanied by Dr. W. J. S. Lockyer and 

 Mr. F. McClean, and assisted by the officers and crew of H.M.S. 

 Vphus, were stationed at Palma, in the island of Majorca. Their 

 observations were inten'upted by clouds. 



On the south of the Mediterranean the weather was much kinder. 

 The party that I was in charge of was stationed at Guelma, in Algeria. 

 We had wondei-ful weather there, and the observations were success- 

 fully carried out under a superbly clear sky. In Tunisia, the 

 Astronomer Royal, assisted by Mr. Dyson, Professor Sampson, and Mr. 

 Atkinson, was stationed at S'fax, on the coast, and there they had fair 

 weather. The last station was in the Soudan, at Assuan, where 

 Professor Turner and Mr. Bellamy, from Oxford University Obser- 

 vatory, were stationed, and had very fine weather conditions. 



I should Uke to show you a slide illustrating the preparations 

 made by Professor Callendar to measure the heat radiation of the 



