“That’s a traverse board,” explained Chester. “I’ll show you how it works. First look under the map. See those marks on the table? They are the points of the compass. When you use the traverse board, you first ‘orient’ it, that is, place it that its bearing is true with the points of the compass, the needle pointing north. Now sit down. Take my telescope and look, say, south. Suppose you see smoke, but can’t exactly locate it. You clamp the arrow to the traverse board, the point toward the smudge, so. Next, you put the map with my station directly over the centre of the traverse, that red dot which I’ve marked, so. Now stick a pin through my lookout and into the centre of the board, then twist the map until its north and south line covers the north and south line of the board, so. Take the range-finder, place its bevelled edge against the pin, raise the sight, no, keep the one with that upright hair away from your eye, and look at your smoke again. With the tables and marks you can quickly get the range and locate it on the map.”
For several minutes Ted squinted along the sights, glanced at the range tables and then at the map.
“I should say it was about there,” he said, putting his finger on a spot south of Bear Mountain.
“Too bad it isn’t pleasant, you might find a real fire to practise on.”
“But I have found one. My eye! but the smoke is getting thick. Yes, I’m sure it’s where I pointed on the map.”
At first the lookout had believed his visitor to be pretending that he had discovered a forest fire, but as he heard his last words, he pushed him from the chair and sighted along the rangefinder.
“You’re right! You’ve located it, Porter. It’s on Carl Petersen’s quarter.”
And springing to his telephone, Chester called for connection with the man who was Jasper Jay’s nearest neighbour, with the exception of the young homesteaders.
CHAPTER XXXII
AN UNEXPECTED ARRIVAL