PRESIDENT'S ADDRESS. 13 



METEOROLOGY. 



It would appear from old records that the freezing of the 

 Thames was a much commoner event in the seventeenth 

 century than in modern times, as Evelyn records no less than 

 seven such freezings in his diary which extends from 1620 to 

 1706, and Pepys, 1660-1669, also records three which are not 

 mentioned by Evelyn. The Thames was also probably frozen 

 in 1657-8 which was a very cold winter, which makes eleven 

 in 84 years or rather more than one in 8 years, which is 

 certainly not the case now. This would suggest that our 

 winters are less severe on an average than 250 years ago and 

 the last very mild winter would perhaps have occasioned 

 surprise to the people of that time. The period from 

 December 21st January 10th was warmer than in any year 

 for the past 80 years, and the mean temperature about 10 

 above the normal. It is stated that the weather for October 

 and November, 1919, was the coldest for 80 years, whilst that 

 for December, 1919, to April, 1920, was the warmest for 80 

 years. Last October was exceptionally warm. So that the 

 weather lately has been curiously uncertain. Last summer 

 was a particularly cool one, about 2 cooler than the normal. 

 The Meteorological Report of the British Antarctic Expedition 

 of 1910 13 has lately been published. The violence of the 

 wind seems to have been very much less than that experienced 

 by the Mawson Expedition at a more westerly station. On 

 May 29th, 1920, a dreadful disaster took place at Louth, the 

 small stream which passes through the town suddenly swelling 

 into a huge flood, rising 15 feet in half-an-hour and carrying 

 away everything, including buildings, in its course. This was 

 caused by a very heavy thunderstorm which fell in that part 

 of Lincolnshire to the extent of about five inches in about two 

 hours and not apparently by any waterspout, though the 

 resemblance to some such phenomenon was noted by at least 

 one observer. The height of a brilliant aurora seen in Norway, 

 on March 22nd, 1920, was measured and found to be about 

 300 miles. The distances at which gunfire was heard caused 



