Besides, the country soon disappeared in one of those sandstorms which are so frequent in these regions. The wind called the "tebbad" bears along the seeds of fever in the impalpable dust it raises in its passage. And many are the caravans that perish in its eddies.

To escape this dust, which might have interfered with the working of the screws, the "Albatross" shot up some six thousand feet into a purer atmosphere.

And thus vanished the Persian frontier and the extensive plains. The speed was not excessive, although there were no rocks ahead, for the mountains marked on the map are of very moderate altitude. But as the ship approached the capital, she had to steer clear of Demavend, whose snowy peak rises some twenty-two thousand feet, and the chain of Elbruz, at whose foot is built Teheran.

As soon as the day broke on the 2nd of July the peak of Demavend appeared above the sandstorm, and the "Albatross" was steered so as to pass over the town, which the wind had wrapped in a mantle of dust.