PART v. VEGETABLE AND ANIMAL LIFE. 59 



about from north to south of the equator, in these days 

 of quick and luxurious steam -voyaging, much may be 

 done. Trying the North African desert, or, better still, 

 the Peak of Teneriffe above the clouds, at one season of 

 the year ; and at another, the rainless West Coast of 

 either South Africa or Australia. Anywhere about there, 

 in British possessions, within a wide limit of latitude, 

 will answer ; if, for the time that the region is to be 

 occupied, a Mason's hygrometer shall show a dry tem- 

 perature between 68 and 90, and a depression of the 

 wet bulb from 15 to 33 . 1 



1 The high temperatures implied between 68 and 90, when further 

 accompanied by clear skies, bright sunshine, and the large hygrometric 

 depressions indicated above, are so provocative of cracked lips, sunburned 

 skin, frizzled hair, etc. etc., as to demand some special protection for the 

 head, its contained " sea of priceless medullary matter," and the face as 

 well. And they always have demanded it. So that all nations, living and 

 working in anything approaching to a natural, open-air manner, have long 

 ago become easily distinguishable by the several kinds of head-dress they have 

 invented and perfected through the ages, to meet -the respective amounts of 

 solar radiation and dryness of air, which their countries may be accustomed 

 to, or afflicted with. 



Thus the Bedouin Arab's bulky headgear, thickly padded above, and 

 drawing closely round the face and over the back of the neck and shoulders, 

 bespeaks a bright zenithal sun and its burning radiations both direct from 

 the sky, and reflected from the bright, barren sand, as well as a parched, 

 arid, skin-drying-up air. 



The Indian Mussulman turban, composed of thirty yards of muslin in 

 length, wound round and round the head, but allowing the last turn or two 

 to be taken about the face when the man is on a journey, speaks much of 

 solar radiations chiefly, and rather less both of reflections from the ground, 

 and of arid air. While there is a still decreasing proportion of these latter 

 features in the rice-fields and sugar plantations of the Southern States of 



