AUTUMN RAIN 153 



north-easterly course ; and it is the conjunction of the 

 structure and path of a normal cyclone which gives us the 

 characteristic succession of winds. The south-west wind 

 tears past us to bend a little to the left and enter the 

 depression from the south ; and the north-west wind is 

 following up the retreating eddy to bend a little to the left 

 in the same way, and enter it a little more from the west. 

 When we face the south-west wind our rule shows that the 

 depression is to the north-westward ; it is still on its way 

 towards us. As we face the north-west wind, the rule shows 

 the centre of the depression to lie to the north-east ; it is 

 now receding from our shores. 



This knowledge of the general route and structure of 

 cyclones in England will help us a great deal to understand 

 and take an interest in the larger processes of the weather. 

 Small cyclones are often very intense ; the violence of a wind 

 depends on the rapidity with which pressure diminishes in a 

 given distance, and the consequent force of the indraught. 

 We can often see very strong but very local cyclonic suction 

 in the eddies a few feet in diameter, which whirl round paper 

 at the street- corners and straws in the stable-yard. In a large 

 cyclone, with its centre speeding across the Iceland seas, the 

 strongest winds may blow from the south-west over our whole 

 islands ; but when the centre of a smaller cyclone passes 

 over the north of England, as it often does, a northerly or 

 north-easterly gale may be blowing in the north of Scotland 

 at the same time as a south-westerly gale on the opposite 

 side of the cyclone in England. The circulation of air in 

 an anticyclone is exactly opposite to that in a cyclone. It 

 radiates outward on a curved path, following the direction 

 of a clock's hands, or the sun. Its typical path is out from 

 an anticyclone, and in to a cyclone in a great double curve 

 like an S ; but this perfect path is usually more or less 



