234 Account of the Climate, 4' c ' Qfthe North of' France. 



and, extending from the sea, envelope all Flanders, but seldom 

 advance interiorly beyond the province of Artois. These fogs 

 occur occasionally at all seasons, but are most common in 

 spring and autumn. 



The quantity of rain is only somewhat greater than at 

 Paris. There, the mean is 24 inches 2 lines, and there are 

 119 days with rain ; here, the mean is 24.4, and the number 

 of days with rain 159. May, July, August, and November 

 are the months in which most lain is observed to fall. 



In spring, the north wind is almost constant, especially from 

 the beginning of March to the middle of April. This wind 

 is strong, dry, cold, and sharp. It freezes in the night, and 

 the barometer always keeps high, but the sky is uniformly ob- 

 scured. Hoar-frosts are apt to occur until May ; and it is 

 not till the middle of that month that the air begins to feel 

 sensibly and steadily warmer. 



In summer, the weather is very variable, there being con- 

 tinual changes from heat to cold, and vice versa, not only 

 from day to day, but in the course of the same day. A fog 

 coming in a direction from the sea, extends all over the coun- 

 try, and then the thermometer sinks. In July and August 

 the heat is considerable, sometimes so high as 92°. On such 

 occasions there is always a perfect calm, but this state of the 

 air never lasts long ; clouds soon begin to make their appear- 

 ance, and the thermometer falls to about 65°. The usual 

 summer heat is from 65° to 80°. At this season, there is al- 

 ways a heavy dew during the night, accompanied by a very 

 cold and dense fog, the thermometer falling from 8° to 14° 

 lower than during the day. Hence the origin of various dis- 

 eases to which persons are liable when exposed to the open 

 air during the night. No where is the sudden sensation of 

 cold at sunset more remarkable. 



In autumn, the weather is most steady ; after the equinox, 

 the thermometer sinks to 50°, and vacillates but little for a 

 considerable length of time. Frosts do not usually com- 

 mence till December ; but during the night and part of the 

 morning, there is always a dense cold fog, which moistens all 

 the surface of the ground, and of solid bodies resting on it. 



In winter, the temperature rarely falls so low as 20°, but it 



