210 PRINCIPLES OF AMERICAN FORESTRY. 



have a chance to become established. If the leaf canopy 

 is rather thin, so that the light has encouraged the growth 

 of grass under the trees, it would be a good plan to break 

 up the soil just before the seed falls, in good years. Pos- 

 sibly furrows could be made through the woodland with 

 a plough; but if too rough for this, then it can be broken 

 up by the dragging of several logs tied together over the 

 land. It would be a good plan to keep out everything 

 but the Sugar Maples, since these will undoubtedly be 

 the most profitable, both for sugar and for fuel. As 

 these seedlings come on they should be encouraged to cover 

 the land, by letting in a little light occasionally, if neces- 

 sary. This may be done by removing some of the old 

 trees that are past their prime. After the young trees 

 are seven or eight feet high, no harm would come from 

 the pasturing of stock among them for a few years, un- 

 less the land was so heavily pastured that the treading 

 of the stock about the roots was injurious. If treated 

 iii this way there should be no trouble about securing a 

 good stand of young Maples to come on and take the place 

 of those which are maturing. 



PROBLEMS BY DR. C. A. SCHENCK. 



The following five problems, numbered 26 to 30, are 

 by Dr. C. A. Schenck, the head of the Biltmore Forest 

 School and an eminent authority on forestry mathe- 

 matics: 



26. A LONGLEAF PINE PROBLEM. 



Premises: Mr. S., of Eastern Florida, owns a Pine forest 

 of all ages, so that seedlings, saplings, poles, and trees 

 are equally mixed, and estimates that the annual growth 

 is 250 feet, board measure, per acre. The tract is 100,000 

 acres, and he thus cuts 25,000,000 feet, board measure, 

 annually with the view of not decreasing the growing 



