44 MADEIRA METEOROLOGIC. PART iv. 



tropics; but on the 26th of June in the northern hemi- 

 sphere there is even still greater solar heat experienced 

 in Madeira's general parallel than under the equator 

 itself. Again, if the ocean becomes electrically charged 

 and desires to find a discharging point, an island in its 

 midst, high enough, as Madeira is, to reach the great 

 environing cloud stratum of the earth, might be most 

 suitable ; in fact a real conductor, if there be plenty of 

 watery vapour in the air round about it. But that, as 

 we have already seen, is Madeira's grand and con- 

 tinual characteristic ; so that neither Lisbon on the 

 Atlantic's eastern coast, nor Malta in the Mediterranean, 

 nor the Azore Islands farther to the north-west, nor yet 

 the Canaries to the south, can compare with Madeira for 

 its nearly perennial current of ascending ocean vapour. 



This is so far, in a general way, in favour of M. 

 Plante's idea ; but for the particular date of occurrence 

 of a special manifestation of it we must look elsewhere. 

 Now when I visited Palermo in the spring of 1872, the 

 astronomers in the Observatorio Reale there, were com- 

 paring the occurrence of their later siroccos from the 

 African coast with special outbreaks of the solar red- 

 prominences ; and were imagining too that the latter had 

 been the agents to pull, as it were, the meteorologic 

 trigger and let the desert climate at that instant explode 

 its long-confined and pent-up breath, at each of such and 

 such particular epochs. Did any such solar manifesta- 

 tion then take place at the time of the peculiar Madeiran 



