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that the comparative height of the barometer as indicating the pressure of the 

 atmosphere over different adjacent districts regulates the force and direction of 

 the wind, but we have yet to learn how " depressions," as they are technically 

 called, are caused, and also what influences lead to their extension, movement, 

 and dispersion or filling up. No doubt the solar heat is the great factor, but then 

 comes the question how far the changes in the Polar ice, the descent of icebergs 

 into more soiithern seas, and the acting and re-acting forces of electricity and 

 magnetism have a secondary influence upon our climate. These are problems, as 

 yet, sufficiently puzzling, and but to a small extent unravelled. The science of 

 meteorology is, however, making rapid strides, and is calculated before long to 

 confer great benefit on mankind. One thing is certain, whatever may be the 

 primary reason of it, that the depressions which usually come to the north of the 

 British Isles have, many of them, this season traversed France and the southern 

 parts of England, causing an unusual downpour of rain in the former country, and 

 heavy snowfall on the Alps — tremendous avalanches having recently overwhelmed 

 several districts in Switzerland — and the awful floods in Hungary having arisen 

 from the same cause. I propose then to consider in this paper what have been the 

 special characteristics of the present season, as regards atmospheric phenomena, as 

 well as the variation of climate which History and experience teach us our English 

 climate undergoes. 



We are dependent principally upon the old chronicles for information as to 

 the endurance of frost and snow in the early times of our history. These notices, 

 though sometimes scant and vague are, nevertheless, often sufficiently circum- 

 stantial to form a pretty reliable basis for comparison, and it would appear as if 

 in former time the rigour and severity of our winter were considerably greater 

 than at present, even allowing for the exaggeration which we often find in old 

 writers. Thus in 2D0 A.D. the Thames was frozen for nine weeks ; in 291, most 

 of the rivers in England for six weeks ; in ."iOS, for two months ; in G95, again the 

 Thames was frozen over six weeks ; in 908, English rivers for two months ; in 

 923, the Thames for 1.3 weeks; in 998, for five weeks; in 1063, for 14 weeks ; in 

 1433, for 11 weeks, as far as Gravesend. Now, if these statements are correct, 

 and I have only extracted those which speak of definite effect produced, they 

 indicate much colder winters than we now experience. The thermometer was 

 not invented till 1590 by the celebrated Sautorius, some say by Drebel, a Dutch- 

 man, in 1G20. It was improved by Reaumur in 1730, and by Fahrenheit in 1794 ; 

 but our observations are not reliable till we get to 1771, and even then, up to 

 1814, there is some doubt of their strict accuracy. From that time to the present 

 we have carefully prepared tables of the records at Greenwich, and also since 1826 

 at the Royal Horticultural Society's grounds at Chiswick. Taking, then, the 

 period from 1771 to 1879, we find that, while there is not much difference in sum- 

 mer, the winter temperature, especially that of January, is some two or three 

 degrees colder in the earlier than in the latter years of the series. Probably this 

 is somewhat due to the increase of London, and the effect of so many fires and 

 houses in warming the adjacent air, and therefore to some extent the comparison 



