[Illustration: Figure 65. The loaded flat cars reach the sawmill where the logs are unloaded and sawn into lumber. During the fiscal year 1917 timber sales on the National Forests brought into the National Treasury almost $1,700,000.00. Photo by the author.] When piling and burning is necessary, all tops and débris, including large chips made from hewing ties, are piled at a safe distance from standing trees. The piles are not allowed to be made in groups of seedlings or young growth, against dead snags, near living trees, or on stumps, large tops or logs, but wherever possible in openings. The piles are adapted to the size of the opening in which they are made and must be made sufficiently compact to kindle easily and burn cleanly. The ideal pile is of medium size, conical in shape, compact, from 5 to 7 feet in diameter at the base and from 4 to 5 feet high. Brush piling and burning is an art which can only be acquired after long experience. Brush is scattered whenever this method promises the best silvicultural results, unless there is serious danger from fire on account of dense timber and reproduction. The scattered brush is intended to afford protection to seedlings from excessive transpiration and from trampling by stock and to protect the soil from erosion. Ground burning may be advisable where clean cutting has been employed, to expose the loose mineral soil for better seed germination. When this method is used the purchaser is required to clear a fire line around the area to be burned and to furnish adequate help to the Forest officer who supervises the burning. Frequently brush is burned as the cutting progresses. Fires are started at convenient points and the brush is thrown on them as it is lopped. Where brush burning is necessary it is not advisable, ordinarily, to burn over an entire sale area. It is frequently possible to burn the brush so as to form broad fire lines, particularly along railroads or wagon roads. The best times for brush burning are after a light fall of snow or rain, early in the spring before the snow has melted or the dry season has begun or during or immediately after summer rains. Brush disposal must always keep pace with logging except when the depth of snow or other reasons make proper disposal impossible. Often the brush must lay in piles at least one season before it becomes dry enough to burn. _Payment for Timber._ Payment must be made for all timber in advance of cutting. This, however, does not imply that one advance payment must be made to cover the stumpage value of all the timber included in the sale. Frequent installments are allowed sufficient usually to cover the cut of one or two months. [Illustration: Figure 66. Scene in Montana. Forest officers constructing a telephone line through the Flathead National Forest.] [Illustration: Figure 67. Forest Ranger, accompanied by a lumberman, marking National Forest timber for cutting in a timber sale. Coconino National Forest, Arizona.]