IMPRESSIONIST SKETCH 313 



so often brings sudden death or the quiet peace of sleep. 

 A similar interpretation holds for the subtle story of 

 Proserpine. 



Ill 



But let us turn from fancy to fact, though, perhaps, 

 there is sometimes more trueness to Nature in the fairy- 

 tale than in scientific text-book. The astronomers tell 

 us of the general law that on either hemisphere 63 per cent, 

 of the total heat of the year is received during Summer 

 and 37 per cent, in Winter ; but this statement, funda- 

 mental as it is, hardly expresses the full force of the case. 

 For the astronomers are thinking, and, from their point 

 of view, rightly, of a year with only two seasons ; therefore, 

 as we are dealing with four, we must refer part of the 37 

 per cent, received in Winter to late Autumn and part to 

 early Spring, leaving Winter poor indeed. 



The same authorities also tell us that the length of 

 Summer and Winter is variable ; thus we have now about 

 1 86 days of Summer and 179 days of Winter (in the two- 

 season sense), while it is but a geological yesterday since in 

 the Ice Ages the Summer lasted for only 166 days, and 199 

 lay in the grasp of Winter. This is again very important, 

 for the total amount of warmth received has obviously to 

 be divided by the number of days in the season to give 

 us a numerical expression of the average daily sun-heat 

 at any given time. Yet, finally, this must not hide from us 

 the commonplace of experience that it is not the average 

 temperature which, so to speak, says yea or nay to this 

 or that form of life ; it is rather the occurrence of certain 

 maxima and minima a terrible heat-wave or a week of 

 very frosty nights. After one exceptionally cold night 

 some years past, over two hundred birds were found dead 

 round the stacks in a small steading. 



