in 1835, at Kendal, Westmoreland. 311 



may be explained the cause of the only periodical wind which 

 we have in this island : I mean that which prevails, generally, 

 from about the middle of April to the 7th or 8th of May, and 

 sometimes longer; as, for instance, in 1835, it prevailed till 

 the 18th, which is later by several days than is usually the 

 case. In Sweden and Norway, the face of the country is 

 covered with snow till the middle of May, or longer. This 

 frozen covering, which has been formed during winter, grows 

 gradually shallower, to the 15th or 16th of May, or until the 

 sun has acquired 17° or 18° of N. declination; while, on the 

 other hand, the valleys and mountains of England have 

 received an accession of temperature of 24° or 25°. On this 

 account, when the temperature of Sweden and Norway is 

 cooled down by snow to 32°, that of Britain is 24° or 25° 

 higher than that of the preceding countries ; because, while 

 the ground is covered with snow, the rays of the sun are in- 

 capable of heating the air above 32° (the freezing point). 

 For this reason, the air of England is 24° or 25° more heated 

 than that of the before-mentioned countries. The air of 

 Sweden and Norway will then, of course, by the laws of com- 

 parative specific gravities, displace that of England, and, from 

 the relative situation of those countries with this country, will 

 produce a n.e. wind. This current is usually stronger by 

 day than by night, because the variation of temperature in 

 the air of Great Britain is at that time the greatest, being 

 frequently from 50° to 60° about noon, and sinking to about 

 32° in the night. 



I do not submit this hypothesis as capable of determining 

 the exact duration, or the existence, of this current of air 

 during the whole of the period I have mentioned, but think it 

 highly probable that it will account for a n.e. wind prevail- 

 ing at this particular season, as observations prove that it 

 does. 



We have had much fewer Appearances of the Aurora Borealis 

 than we have had for several Years past. One of the most 

 remarkable occurred on Nov. 18. The source of the electric 

 light was not confined to the north, but seemed equally dif- 

 fused through the whole horizon ; and the streams of light 

 darted from almost every point of the compass to the zenith. 

 The greatest quantity, during the time I observed it, issued 

 from the s.e. by s. The streamers were not, in general, in 

 compact streaks of light, but resembled sheets of steam highly 

 illuminated ; and, when they reached the zenith, they gene- 

 rally formed into a cloudy appearance, in shape similar to the 

 cloud called the mare's tail. Several times imperfect streaks 

 of light, of a more compact form, stretched across from west to 



