While the reforestation of the watersheds of streams important for irrigation and municipal water supply has a large financial value, this value is hard to estimate because it involves not actual cash profit but loss prevented. But when a favorable site is planted to a quick-growing, valuable, species, it is comparatively easy to arrive at a fair estimate of the possible profit on money invested. It has been estimated that under many conditions it is highly profitable to reforest waste lands on the National Forests by planting. From certain experiments made it is estimated that a white pine forest artificially established on a second-class forest soil in Minnesota, will yield about 46,500 board feet per acre in 50 years, worth at least $10 per thousand feet, or $465 per acre. Figuring the cost of planting and the cost of care and protection per acre per year at 3 per cent. compound interest gives a total cost of $34.07 per acre at the time the timber is cut and a net profit of $8.62 per acre per year. Douglas fir in the Northwest will produce 81,000 board feet in 80 years, worth at least $8.50 per thousand feet. After deducting all expenses this would leave a net profit of $555.30 in 80 years or about $6.94 per acre per year. These profits are indeed large, considering that the land is not capable of producing cereal or vegetable crops profitably. And it must be remembered that in all the above calculations all the money invested is earning 3 per cent. compound interest and that the net profits are the earnings in excess of this 3 per cent. interest. The little trees that are set out on the National Forests every year are produced in large nurseries, where they are grown by the millions. In these nurseries the little trees receive the most expert care from the time the seeds germinate until the time they are large enough to withstand the rigors of wind and weather on the barren hillsides of Uncle Sam's Forests. The seeds are first carefully sown in seed beds and left to develop in these from one to three years. At the end of one year they may be transplanted in nursery rows where they will have more room to develop. Rapidly growing species like yellow pine are kept only a year in the seed bed and perhaps one or two years in the transplant beds; but slow growing species, like cedar, must remain in the seed beds two years and usually two years in the transplant beds. All this depends upon the species and the site upon which it is to be planted.