[Illustration: Chestnut plantation, thirty years old. Photo by U. S. Forest Service.] 4. As a protection on a steep up-lands against erosion, the chief thing is to establish a forest cover. The composition of the stand is more or less immaterial although it is always desirable that the most readily marketable species shall be used so that the woodlands in addition to performing their protective function may also supply an actual revenue. Therefore, as far as possible, the trees to be used should be the ashes, oak, chestnut, hickories, maples and other species, whose value in the lumber market is standard. The chief feature in regard to this protective woodland is that the forest cover shall remain unbroken. 5. As a means of regeneration of worn out land, especially hillsides, which are liable to erosion and do not lend themselves easily to a scientific rotation of crops, a forest cover is a very important factor since it furnishes to the soil the essential humus and, when such species as the black locust or honey locust are planted, it furnishes the nitrogenous elements to the soil, since the locusts are legumes and produce on their roots nodules of nitrifying organisms similar to those found on the roots of alfalfa, cow-peas or soy beans. 6. As a general proposition, the raising of lumber or timber by an individual is out of the question on account of the length of time which it takes to grow the better grades of this material. Ordinarily, a tree fifty years old will furnish only the poorest grades of lumber and usually only small dimension stock. Generally speaking, one hundred years is not too small a calculation for the length of rotation when lumber is the aim. In the event that any individual plants trees for the production of the lumber, such planting is done as an investment purely and simply since he can not expect to see the crop harvested within his life time. The only monetary benefit that could possibly accrue to the owner is from the material which may have to be thinned out or in the event that he should desire to sell his farm when the existence of a grove or woodland of healthy young trees would represent an actual money value to the purchaser. In case planting for this reason is made, the trees should be those which are the most valuable lumber producing species, as for instance, the oaks, the ashes, hickory, sweet gum, tulip poplar, white and yellow pines, basswood and a few others. 7. It may be that in connection with the farm the presence of a grove of trees thereon will represent a value from the aesthetic and science standpoint where the beauty of the landscape is a matter of consideration to the owner of the land, or to any one who might desire to purchase it. In this event the kind of tree is not so important as the actual presence of trees of some kind. The general effect is the main consideration, without regard to the individual features which compose this effect. FOREST TAXATION.