Now all this is very well, this leaving it to Nature to fertilize the fields, where everything is just right for it, as it is along the Nile, but in most lands it won't do it all. The trouble is that, in raising the grain foods, the ground must be kept free of grass and weeds, and well ploughed during the rainy season. But the same rains that water the fields wash more or less good soil into the streams; much more than Nature alone can put back. For instance, down in Italy where, if the old forests were still there, the rains wouldn't wash away more than a foot of soil in 5,000 years, this soil is being carried into the Po, and by the Po emptied into the sea so fast--a foot in less than 1,000 years--that if you visit Italy to-day, say, and then go back in ten years, you'll see bare rocks on many a hillside that is now clothed in green. On such rocks the soil is already thin, and in ten years more it is all gone; all washed away! This thing is going on all around the shores of the Mediterranean. You are constantly coming on sections of country that used to be covered with great forests and prosperous farming communities where the soil has vanished, and many stretches of barren, rocky land where hardly a weed can find a foothold. [Illustration: WHAT HAPPENS TO THE LAND WHEN THE TREES ARE GONE Could anything be more desolate? You can see from this example how vital to our national life is the forest conservation work of our government. Trees, by the network of their roots, keep the soil from washing away, retain moisture by their shade, and absorb the water of the rains and the melting snows so that it reaches the rivers and the creeks gradually. But when the trees are gone the water, unchecked, rushes down the slopes in floods, washing away the precious soil and leaving them as barren as a desert.] "But, what are you going to do about it?" you say. "You can't change the slope of the hills, can you? And the farmer has _got_ to plough his land--you just said so yourself." Yes, he's got to plough his land, to be sure; but so has he got to have pasture for his live stock. If he hasn't any live stock, that just shows what kind of a farmer he is. Every farmer ought to have live stock. Corn always brings a great deal more when it goes to market "on four feet," as the saying is; and, besides, the live stock give back to the fields, in the shape of manure, a large part of what they eat. Now, if you have live stock you must have pasture, and all land with a slope of more than one foot in thirty should be used partly for pasture and partly to grow wood for the kitchen stove, and hickory-nuts and walnuts for winter firesides. Although the land slopes, the mat made by the grass roots will keep it from washing away. "But suppose you lived where there wasn't any land to speak of that didn't tip up; in New England, say--what would you do then?"