“You see that man over there on the hillside,” said Uncle Paul, pointing to a laborer who, with a large hoe, was paring the ground, so to speak, by shaving off great squares of earth covered with grass and weeds and shrubs. “You see how he stands those pieces up, either in pairs, back to back, or one at a time, so bent or vaulted that they will stay upright by themselves. Thus the air is allowed to circulate and dry them rapidly. If we come back in a few days, after sun and air have done their work and the drying process is complete, we shall find our man there again at his work; and we shall see how he piles up the turf with the earthy side upward and outward. In the middle of the pile he leaves a cavity which he fills with brushwood and dry leaves. Then he sets fire to the whole. A second pile is constructed in the same manner and likewise set on fire. Soon the entire hillside is covered with a great number of these small furnaces, burning slowly and sending out long trails of smoke. In a few days, three or four at most, the fires burn themselves out, and then, as soon as all the piles are cold, the mixture of ashes and calcined earth is spread over the ground with a shovel. This agricultural operation is known as paring and burning, and is carried out for the purpose of rendering arable a tract of land not yet under cultivation and still covered with wild vegetation. “The operation of paring and burning produces two effects, one with reference to the clay in the soil, the other having to do with the ashes left from the burning of the weeds. Clay, as you know, is a tenacious, binding substance, impervious to both air and water. Consequently a soil that is too clayey is unfavorable for vegetation, furnishing the roots with insufficient air and moisture. Now, when clay is heated to a high temperature, it acquires very different properties: it no longer makes paste by the addition of water, but is porous, permeable, and readily admits air and water. The paring-and-burning process, therefore, improves an argillaceous soil by calcining the clay and rendering it permeable. That is as much as to say that if paring and burning are beneficial to heavy or clayey soils, they are, on the other hand, harmful to those that are light or sandy.