76 PENETRATING POWERS OF DRY COLD. 



blow, and though it may seem absurd to the ears of 

 the general reader, a good warm ulster is a very 

 necessary part of a traveller's outfit for nightwork in 

 these regions. In the Empire of Morocco the Bedouins 

 all have a sort of long, thick, brown-striped woollen 

 garment, made of native cloth and furnished with a 

 hood, called] a " haik," for this purpose, which can 

 with a little trouble be easily adapted for the use of 

 Europeans. Before the days of ulsters, the author 

 found this haik a good and efficient substitute for that 

 now almost indispensable garment, which has contri- 

 buted so largely to the comfort and health of modern 

 travellers. 



Of course it goes without saying, that for a traveller 

 to be without ample protection against the sudden 

 falls of temperature at night, and especially against 

 the bitter chill of the small hours of the morning, is 

 one of the surest ways of laying the seeds of fever, 

 rheumatism, or some other serious ailment a matter 

 which we shall have a good deal to say upon here- 

 after, in the proper place. But barring accidents 

 from this preventable cause, the beneficial effects of 

 these cool nights in bracing up the constitution against 

 the exhausting heat of the day, is very marked. 



Hence it comes that these very high temperatures 

 are not found to produce the same evil effects as the 

 considerably lower ones met with in damp, steamy, 

 tropical climates. The dry zone of desert countries 

 which extends across the continents of Asia and Africa, 

 is therefore comparatively healthy notwithstanding that 

 they comprise within their limits what are probably 

 the hottest countries in the world that is to say, 

 those countries where the range of the thermometer 



