president's address. 27 



very vivid even now, after an interval of so many years. The 

 beauty of the corona on these occasions, especially when the sky 

 is free from cloud, is always admired for its silvery whiteness ; 

 while in the telescope rose-coloured solar prominences, consisting 

 of incandescent hydrogen gas, are usually seen shooting out 

 from the sun at the edge of the dark body of the moon, to an 

 occasional height of 100,000 milesor more. At Christiania, the 

 dark shadow-path was seen to approach gradually from the 

 west, and after the few minutes of total darkness, it was noticed 

 to pass as gradually away towards the east. The varying effects 

 of light and shade on the landscape and on the waters of the 

 Fiord was a sight worth a long journey to see. 



Since the construction of the powerful space-penetrating 

 telescopes, with which almost every observatory of importance 

 is now furnished, great attention has been given to the 

 delineation of the special features observed on the discs of the 

 planets Mars, Jupiter, and Saturn. The changes of detail that 

 are continually visible on the surfaces of these interesting 

 planets show that they are subject to atmospheric storms of far 

 greater magnitude than what we experience on the earth. For 

 example, we see on Jupiter aU the signs of great atmospheric 

 disturbances, produced by forces indicating the existence of very 

 strong winds, bearing some analogy to our trade winds. The 

 cloud-like formations are sometimes seen to change so rapidly in 

 shape, that they can hardly be accounted for except by supposing 

 that large quantities of rain has fallen, and thus new clouds 

 would naturally be formed ; or else that great cloud-masses have 

 been driven along with enormous rapidity by immense currents 

 of air moving with the velocity of a hurricane. It has been 

 calculated that this velocity of the wind cannot be less than two 

 hundred miles in an hour. The physical features of Jupiter are 

 interesting subjects of study to the amateur astronomer, as all 

 the variations in the form of the belts are easily distinguished 

 in most ordinary telescopes ; and what these features are have 

 been well shown in most of the beautiful drawings that have 

 been made of this giant planet in recent years. During the last 

 twelve years an enormous red spot of an oval form has been 

 peculiarly attractive. Other spots of a reddish colour, and some 

 almost a pure white, are occasionally noticed, but these are not 



