"Perhaps you will have the goodness to explain."
"I will do so, and you will soon allow that I am correct. Listen, Mr. Edward, for this is important to know."
"I am listening, my good fellow."
"You are not ignorant," the hunter continued imperturbably, "that what is conventionally called the desert is largely populated."
"Quite true," the young man said, smiling.
"Good; but the enemies most to be feared in the prairies are not wild beasts so much as men; the Indians and hunters are so well aware of this fact that they try as much as possible to destroy all traces of their passage and hide their presence."
"I admit that."
"Very good; when the Redskins or the hunters are obliged to light a fire, either to prepare their food or ward off the cold, they select most carefully the wood they intend to burn, and never employ any but dry wood."
"Hum! I do not see the use of that."
"You will soon understand me," the hunter continued; "dry wood only produces a bluish smoke, which is difficult to detect from the sky, and this renders it invisible at a short distance; while on the other hand, green wood, through its dampness, produces a white dense smoke, which reveals for a long distance the presence of those who kindle it. This is the reason why, by a mere inspection of that smoke, I told you just now that the people down there were white men, and strangers, moreover, to the prairie, else they would have employed dry wood."