less degree, but particularly towards the south, the unexplored
portions of Ahaggar stood out as far too numerous white patches in the
tan area of supposed mountains.

I finally said:

"You give me your word that when you have seen these famous grottos,
you will make straight for Timissao by Tit and Silet?"

He looked at me uncomprehendingly.

"Why do you ask that?"

"Because, if you promise me that,--provided, of course, that my
company is not unwelcome to you--I will go with you. Either way, I
shall have two hundred kilometers to go. I shall strike for
Shikh-Salah from the south, instead of from the west--that is the only
difference."

Morhange looked at me with emotion.

"Why do you do this?" he murmured.

"My dear fellow," I said (it was the first time that I had addressed
Morhange in this familiar way), "my dear fellow, I have a sense which
becomes marvellously acute in the desert, the sense of danger. I gave
you a slight proof of it yesterday morning, at the coming of the
storm. With all your knowledge of rock inscriptions, you seem to me to
have no very exact idea of what kind of place Ahaggar is, nor what may
be in store for you there. On that account, I should be just as well