1 22 DUST COLUMNS. ch. v. 



of the Oued Nyfs, but this is only imperfectly seen from 

 the neighbourhood of Marocco. 



The day was hotter than any we had yet experienced, 

 the temperature in the shade being about 85° Fahr., and 

 the breeze which usually rises during the hottest hours 

 was scarcely felt. But the vicinity of lofty mountains 

 usually determines strong currents in the heated air, and 

 these must have been at work, though unfelt by us. As 

 we looked towards the mountain chain, we noticed lofty 

 columns of sand or dust, remarkably uniform in shape, 

 that travelled steadily westward across the plain in the 

 opposite direction to the breeze, so far as this could be 

 detected. At one time as many as three of these were 

 seen at the same time, each moving independently. 

 These miniature cyclones, arising from the interference of 

 opposite currents of air, are not uncommon in the plains 

 on the south side of the Alps, but are rarely to be seen on 

 so great a scale as here. 



About two hours after starting, the great tower of the 

 chief mosque came into view, and one of our soldiers 

 rode on ahead to announce our approach. Not long after- 

 wards we met a courier boimd for Mogador with letters 

 for Mr. Carstensen, and we took the opportunity of 

 reporting progress and sending him a few details as to our 

 journey. In default of regular postal communication, 

 which is not to be thought of in such a country, the facility 

 for forwarding letters in Marocco is far greater than could 

 be expected. For a few shillings a native is easily induced 

 to make a journey of many days, and take care of letters, 

 which always reach their destination. The reverence with 

 which Mohammedan people generally regard all written 

 communications — which may perchance contain the name 

 of Allah — serves as a protection so effectual, tliat the loss 

 of letters and despatches is scarcely ever heard of. These 

 couriers ( ravel forty or even fifty miles a day, and after a day's 

 rest are ready to return to the place whence they came. 

 The chief object of Mr. Carstensen's letter to Marocco had 



