It is a beautifully simple process. Driven into these regions by some compelling current of the upper atmosphere comes a mass of warm air laden with moisture--a cloud. As it comes in contact with the cold air of the region it parts with its heat, and the temperature of the lower air rises. Having parted with its heat, it can no longer contain its moisture; and, having parted with its moisture, it ceases to exist. The cold of the earth and of its immediate air envelope has seized upon that cloud and devoured it, and the cold resumes its sway. So have I opened the door of a crowded cabin, when an Indian dance or other gathering was in progress, at 50° or 60° below zero, and the cold, dry air meeting the hot, moist air has caused an immediate fall of snow on the threshold. After the abrupt rise in temperature on Christmas Day, the snow began to fall heavily, with a barometer continually falling until it reached 27.98 inches, the lowest point recorded here (at an elevation of about 500 feet above the sea) in two years and a half--and before the snow ceased three feet had fallen. Our winter itinerary called us to leave the Allakaket immediately after New Year's Day, and our route lay overland through a totally uninhabited country for nearly one hundred and fifty miles, to Tanana on the Yukon. We knew that it would not greatly interfere with our plans to lie another week at the Allakaket, and that would bring our departure after the monthly journey of the mail-carrier and would thus compel him to break trail for us through all that snow. That is the way the mail-carriers in Alaska are usually treated, but Arthur and I took some pride in keeping as closely as possible to the announced dates of visitation and in doing such share of trail breaking as fell to us. [Sidenote: TRAIL BREAKING]