THE AURORA BOREALIS. 727 



in Norway 1,300 metres high, saw brilliant rays of Aurora 

 across a thin mist which glowed with a remarkable light. To his 

 astonishment, an incomprehensible muttering caught his ear; 

 when this ceased he perceived a very strong smell of sulphur 

 almost suffocating him. 



15. Observations of Aurora in Italy, during April 1871, by 

 M. Denza. (Archives des Sciences, No. 41, 1871.) 



Auroras were remarkably frequent in Italy, as elsewhere, 

 in April 1871. On the 9th a remarkable Aurora was seen, occu- 

 pying an extensive region between Perseus and Cassiopea, and 

 lasting until midnight. During the day, at mid-day, there had 

 been a beautiful solar halo about 35° in diameter, changing from 

 white to red and other colours, followed by a thunderstorm, with 

 a falling barometer and the declinometer deflected more than 

 usual towards the east. On the morning of the 10th the decli- 

 nometer continued to be deflected, and at mid-day ninety-seven 

 spots were counted on the Sun's disc, whereas on the 9th there 

 had only been sixty-three. 



On the 18 th of April there was a similar Aurora, but consisting 

 of two phases, the second more brilliant than the first and lasting 

 through the day up to 10 at night. From this time until the 

 23rd of April the Aurora appeared every day, giving a reddish 

 tinge in the north and north-west. It made a brilliant contrast 

 with the zodiacal light, which at the same time shone out very 

 brilliantly. 



On the evening of the 23rd the Aurora shone out brilliantly, at 

 first at 8.15 with a rosy tint about 20° on the horizon, then soon 

 after 9 o'clock it shone out very brilliantly for five or six minutes 

 and then waned. Before and after the display the northern sky 

 was covered with a reddish- white light. 



On the evenings when the Aurora appeared, the magnetometers 

 were agitated throughout Italy, and the disturbances ended by a 

 very violent agitation during the whole of the 24th of the month. 

 During this time numerous sun spots were observed at Rome, 

 Palermo, and at Moncalieri \ but the greatest number was observed 

 on the days of the Aurora. 



There were also displays of Aurora seen at Moncalieri in June, 

 the most brilliant on June 18, which was accompanied by a very 

 violent magnetic disturbance. 



[The winter of 1870 was remarkable, not only for the number 

 of Auroras, but also for their great brilliancy and their very 

 great extent. The third volume of " Nature " contains accounts 

 of several displays seen in various parts of the world. 



The displays of Oct. 24 and 25 were remarkably brilliant in 

 England and in America, and the Aurora Australis was seen on 

 the same days at Madras ; yellowish-white and crimson beams 

 shot up from a bank of light in the southern horizon. These 

 displays ware seen in the daytime in England and America as 



