He had not set the mill afire.

That would have been profitable from no standpoint, and he had no grudge against Jean Jacques.

Why should he have a grudge?
Jean Jacques' good fortune, as things were, made his own good fortune; for he ate and drank and slept and was clothed at his son-in-law's expense.

But he guessed accurately who had set the mill on fire, and that it was done accidentally.

He remembered that a man who smoked bad tobacco which had to be lighted over and over again, threw a burning match down after applying it to his pipe.