50 METEOROLOGICAL 
first quarter. ‘Occasionally, as on the 7th January, 
1831, printed characters could be read without 
difficulty.’ Indeed, the intensity of the Northern 
or Polar light is sometimes very great; and 
Lowenorn assures us, that on the 29th June, 1786, 
he recognized the coruscation (trembling motion) 
of the Aurora Borealis in bright sunshine. 
Some splendid manifestations of the Aurora 
Australis, or Southern hght, were witnessed by 
Captain J. Ross in his voyage to the South Pole.* — 
These Southern lights have often been seen in 
England by Dalton, and Northern hghts have been 
witnessed in the Southern hemisphere—14th Ja- 
nuary, 1831—as far as 45 degrees latitude. 
It has been shown, by many experiments, that 
the electric hght, whatever be its source, does not 
show any signs of polarization. Now this has been 
lately proved to be the case with the light of the 
Aurora, which shows no polarization, according to 
Mr. Rankine; but when itis viewed reflected from 
the surface of a river, polarization is detected, 
—which proves that in the former case the want 
of polarization is not owing to the weakness of 
the Aurora observed. 
A curious phenomenon was noted by Admiral 
Wrangel, when he was on the Siberian coast of the 
Polar Sea. He observed, that during an Aurora 
* The Aurora Australis was seen for the first time by Captain 
Cook in his first voyage, and again in his second voyage. 
