78 FROM AN EASY CHAIR 



which does not attack man as does the Cheops flea. 

 The disappearance of plague in Western Europe seems 

 to correspond in date with the arrival of the Grey rat. 

 But, on the other hand, an alteration in the character 

 of our houses and their greater " accommodation " for 

 the new rat rather than the old black species may 

 account both for the increase of the latter and for 

 the absence of dirt and vermin in the dwelling-rooms 

 and bed-chambers which formerly enabled the plague- 

 bacillus to flourish amongst us, and to reach the human 

 population as it does now in India and China. All 

 this shows how necessary it is to have accurate true 

 knowledge of such despised creatures as rats and fleas, 

 if we are to live in great crowded cities closely packed 

 together. And it should also make us try to gain 

 further knowledge as to these creatures, so that we 

 may form a reasonable anticipation of the consequences 

 we are bringing down on our heads when we set about 

 exterminating this or that race of animals. We are 

 not yet sure that the Norwegian Grey rat is not a 

 blessing in disguise. 



31. Ancient Temples and Astronomy 



Janssen, the French astronomer, who died about the 

 same time as Lord Kelvin, acquired celebrity by his 

 discovery of a method for seeing and studying the great 

 flames or prominences which surround the sun. The 

 glare of the great fiery ball is such that the eye is 

 blinded in ordinary circumstances to the light of 

 these prominences. They were only known from their 

 coming into view during the total eclipse of the sun^s 

 disc by the moon. Then they were seen as a great 

 fringe of pointed, tongue-like flames around the 

 darkened disc. But at other times no use of smoked 

 glass or telescope could bring them into view. Janssen 



