How do you know that they crossed, and why did you not tell us ?" "I did not know until I saw the fires over yonder." "And how did they tell you ?" "Tut, an Indian papoose could have told," said Du Lhut impatiently.
"Iroquois on the trail do nothing without an object.

They have an object then in showing that smoke.

If their war-parties were over yonder there would be no object.

Therefore their braves must have crossed the river.

And they could not get over to the north without being seen from the fort.