44 4 Mr. J. K. Laughton on the Natural Forces that 



mean for July at Abousheer, 111° as occasional in the Red Sea, 

 In Central Australia, according to Captain Sturt, the thermo- 

 meter rose every day to 112° or 116°, and on at least one occa- 

 sion (on January 21st) to 131° in the shade; and the testimony 

 of other explorers is to the same effect. Compared with such 

 high temperatures, the 82° of the equator sink into insignifi- 

 cance ; and it is clear that if the expansion of the air by heat pro- 

 duces a sensible wind, then we must find during the summer 

 months a westerly wind prevalent on the coast of Africa between 

 the latitudes of 20° and 30° N., between which parallels the 

 great Desert is for the most part situated, — as also a south- 

 easterly wind on the southern coast of Arabia, and a north- 

 westerly on the north-west coast of Australia. These winds we 

 do not find. I am at present unable to tabulate the winds on 

 the Australian coast ; but I have before me the star-charts pub- 

 lished by the Royal Meteorological Institute of Holland, which 

 show for the month of January a marked prevalence of winds 

 from the W.S.W., blowing, that is, nearly parallel to the coast; 

 whilst in February there is as marked a preponderance of winds 

 from the S.W. The following Table (compiled from Maury's 

 Pilot-Charts), in which, for the convenience of comparison, 1000 

 has been taken as the total number of observations in each case, 

 will throw a clearer light on the winds that prevail on the coasts 

 of the African and Arabian deserts during the months of June, 

 July, and August : — 



Latitude , . 



Coast of the Sahara. 



Coast of Arabia. 



Coast of Guinea. 



o 



30-35 N. 



o o 



25-30 N. 



O O 



20-25 N. 



o 



10-15 N. 



10-15 N. 



o o 



10-15 N. 



5-10 N. 



o o 



5-10 N. 



Longitude. 



10-15 W. 



15-20 W. 



15-20W. 



45-50 E. 



50-55 E. 



55-60 E. 



10-15 W. 



15-20 W. 



No. of obs. 



75 



115 



48 



165 



123 



65 



296 



1700 



N. 



266-7 



1391 



270-8 



36-4 



24-4 







41 



N.N.E. 



3867 



295-6 



479-2 



61 



8-1 





6>8 



1-2 



N.E. 



80-0 



208-7 



62 5 



60-6 



24-4 







2-4 



E.N.E. 



400 



104-3 



20-8 



61 



16-3 







41 



E. 





261 





61 



16-3 







41 



E.S.E. 





261 





24-2 



16-3 



15-4 



13-5 



16-5 



S.E. 









24-2 



56-9 





6-8 



21-2 



S.S.E. 





52-2 





61 



89-4 





131-8 



1576 



S. 









970 



97-6 



15-4 



2263 



294-7 



s.s.w. 







125 



60-6 



2520 



169-2 



418-9 



268-8 



S.W. 





8-7 





3151 



284-6 



769-2 



91-2 



86-5 



w.s.w. 



13-3 







109-1 



24-4 



30-8 



67-5 



65-9 



w. 





87 





66-7 



24-4 







21-2 



W.N.W. 



53-3 



17-4 





36-3 







6-8 



29 



N.W. 



400 



34-8 





78-8 









3-5 



N.N.W. 



1067 



69-6 



20-8 



48-5 



8-1 







5-3 



Calm. 



13-3 



8-7 



208 



18-2 



56-9 





30-4 



40-0 



