DISCUSSION AND ANALYSIS OF WINDS. 



741 



room, Trebizonde and Constantinople, given by Prof. Coffin in his "Winds of the 

 Northern Hemisphere." I have shown that so far as the summer is concerned, we 

 cannot accept this conclusion. At Constantinople and Trebizonde the winds are 

 too strongly influenced by locality, and Erzeroom is too high to warrant an applica- 

 tion to the lower regions. Besides this, at other stations, better situated, the winds 

 are westerly. As to the winter, and especially the autumn, I have no difficulty in 

 admitting prevailing N. and E. winds in Trans-Caucasia and Asia Minor, but these 

 are winds which have not the constancy of the trades. (See Plates 6, 7 and 14.) 

 I should say that the erroneous opinion in regard to the extension of the trades 

 cannot be imputed to Prof. Coffin.^ The number of stations was so small when he 

 wrote his book (1853), that he wisely refrained from a conclusion.' 



NORTH AFRICA. 



In Africa north of the equator the winds are as given in percentages in the 

 following table: — 





Juno to August. 



De 



cember to Fc 



bruary. 





H 





w 





i 





M 





W 





H 





;;; 





^ 





;5 



fc 



H 



m 



03 



m 



&: 



fe 



te 



» 



w 



aj 



03 



lA 



^ 



1? 



Eastern Africa — 



























— 



















Zone 12. Alexandria and Port Said 



34 



5 



2 



2 



3 



3 



9 



42 



9 



9 



4 



fi 



10 



21 



^3 



18 



" 12. Cairo and Ismailia .... 



48 



IG 



9 



1 



2 







1 



24 



21 



Ifi 



2 



1 



5 







18 



35 



" 13. N. 73(a). Suez .... 



43 



1 



tl 



(.1 



2 



4 



1 



49 



33 



3 



1 



? 



fi 



11 



11 



33 



" 13. N. 72. \V. Egypt (Oases) 



87 



2 



1 



u 











9 







37 



5 



5 



? 



1 



fi 



^6 



18 



" 13. N. 74. Upper Egypt 



















59, 







4 







4 



8 



4 



'^8 



" 14. N. 29. N. W. Nubia 



















94 



















1 



1 



H 



" 16. N. 25. Sennaar, Nubia . 



U 







2 



4 



71 



14 



7 



?, 



9^ 







n 7 



n 



4 











a 



W. and Central Africa — 



































" 12. N. 173. Tripoli .... 



15 



26 



21 



20 



fi 



1 



2 



7 



















" 13. N. 71(a). Murzonk. 



















17 



fi 



10 



3 



5 



10 



?.H 



21 



" 11. Northern Algeria^ .... 



is 



1:0 



7 



3 



5 



8 



8 



31 



8 



n 



4 



11 



4 



Ifi 



14 



30 



" l(i. N. 24(6). Goree, Cape Verde . 



13 



12 



1 



3 



6 



15 



31 



19 



24 



50 



23 



1 















1 



" IG. Kouka, Borneo .... 



2 



3 



1 



3 



11 



55 



22 







23 



50 



fi 



n 















21 



" 17. N. 33(a). Christiansborg, Guinea at 



































7 A. M 



1 















0.4 



24 



19 



64 



6 



?, 















1 



0.4 



89 



The same at noon .... 











u 



0.3 



0.5 



99 



1! 



0.1 



0.4 



1.5 



1.2 



4 



1.1 



89 



2 



7.5 



To express the general features of the climate of Africa north of the equator, 

 it may be said that N. of 17° N. northerly winds prevail the whole year, especially 

 in the south of this zone, and south of 17° N. the winds are north in the winter 

 and south in the summer. (See Plates 5 and 14.) 



The division-line of about 17° is the zone of lowest pressure in summer. From 

 the north air is drawn towards it from the Mediterranean, producing a wind similar 

 to the trade in its constancy and other features. From the S. air is drawn in from 

 the equatorial parts of the Atlantic and Indian oceans, and, coming over a great 

 extent of warm sea, it brings clouds and rain as in the case of the Asiatic monsoon. 



For example, p. 13*7 of the "Winds of the Northern Hemisphere." 

 Mean of Algiers, Oran, Mostaganem, Setif, Oum-Theboul. 



