"Milking?" questioned the boy in surprise, doubting if he had heard the word aright. Just then Magee replied over his shoulder. "Yes, milking, of course. Didn't you know they had cows here to do all the work? Sure! You've read of the cleverness of ants? Well, they're no better than fools compared to John River cows. They have a regular system. The cows up here have immensely long horns and two of them catch the end of one horn in the bow of the canoe, and another one, a mooley cow, shoves behind, and there you are. That's what they call milking--milking the brush, up here. Don't you expect to go up the John by milking the brush?" he added, turning to Rivers. "Certainly," replied the geologist, then, seeing the lad's confusion, he continued, "but you mustn't mind Magee; milking the brush isn't quite that. It's a term used to specify that way of traveling which consists of pulling the canoes up stream by the boughs of branches along the bank. You see the John River is so swift that, if we were to depend only on paddling and poling, progress would be extremely slow." "But how about tracking?" suggested the boy. "What is to prevent the canoes being pulled along by ropes from the shore?" "The timber and brush come right down to the water's edge," was the reply. "There are no bars and level banks such as there were in the upper part of the Dall River, just before we came to the portage, and of course it is almost out of the question to pull or tow a canoe, when the banks are so thick that you would have to cut a trail in order to get through yourself. The trees and undergrowth overhang the river for quite a distance. Therefore all that can be done is to pull the boats up along the branches, hand over hand, one man poling in the stern. Of course, every few yards the boats get entangled and have to be pushed and pulled out. It's the only way, but it's back-breaking work." It was, there was no doubt about that, and Roger added another chapter to his ideas of what hard work meant. The current of the river was so swift that it was useless to try and paddle up against it, while keeping in the middle of the stream, the banks were so thick and wooded that tracking was impossible, and "milking the brush" required incredible labor, because it meant keeping the canoe so near the bank that it was grounding or striking snags or becoming entangled in roots constantly, or misbehaving itself in some way. [Illustration: IN ICY WATER UNDER A BURNING SUN. Taking a canoe up a glacier-fed current in the height of an Alaskan summer. _Photograph by U.S.G.S._]