It was about eleven o'clock when a peculiar sound awoke the travellers from their reverie. The noise was a kind of whistle, something like that which is produced by opening a bottle of mineral water, but increased tenfold. One might have imagined it was caused by steam blowing off from the safety-valve of a boiler.
The carriage stopped. The postillion could hardly hold his horses. Ahmet, anxious to know what the matter was, hastily let down the window of the chaise.
"What is the matter?" he cried. "Why do not you go on? What is that noise?"
"It is caused by the mud volcanoes," replied the postillion.
"Mud volcanoes!" cried Kéraban. "Whoever heard of 'mud volcanoes!' This is certainly a pleasant way you are taking us, nephew Ahmet!"
"Seigneur Kéraban, you and your companions had better descend," said the postillion.
"Descend!" exclaimed Kéraban.
"Yes. I must trouble you to follow the chaise on foot, as I cannot manage the horses, and they may run away."
"Let us do so," said Ahmet. "The man is right. We must get out."
"There are five or six versts to be traversed," added the postillion: "perhaps eight, but no more."
"Will you decide, uncle?" said Ahmet.
"Let us get out, Kéraban," said Van Mitten. "We must see what kind of phenomena these mud volcanoes are."
Kéraban consented, but not without protest. They all quitted the carriage and walked behind the chaise, which only advanced at a slow pace, guided by the light of the lamps. The night was very dark. If the Dutchman had any expectation of seeing the mud volcanoes, he was disappointed; but, unless one were deaf, it would have been impossible to avoid hearing the curions hissing sound they emitted.
Had it been daylight they would have seen an immense steppe, upon which had been puffed up on all sides little eruptive cones, like the large ant-hills one meets with in
