"To make each day a critic on the last," was the aspiration of a wise man, if not a great poet. So the farmer who will keep careful and candid accounts With himself, annually correcting his estimates by the light of experience, will soon learn what crops he may reasonably expect to grow at a profit, and to reject such as are likely to involve him in loss; and he who, having done this, shall blend common sense with industry, will have no reason to complain thereafter that there is no profit in farming, and no chance of achieving wealth by pursuing it. XXXVI. STONE ON A FARM. This earth, geologists say, was once an immense expanse of heated vapor, which, gradually cooling at its surface, as it whirled and sped through space, contracted and formed a crust, which we know as Rock or Stone. This crust has since been broken through, and tilted up into ranges of mountains and hills, by the action of internal fires, by the transmutation of solid bodies into more expansive gases; and the fragments torn away from the sharper edges of upheaved masses of granite, quartz, or sandstone, having been frozen into iceberg, floating, or soon to be so, have been carried all over the surface of our planet, and dropped upon the greater part, as those icebergs were ultimately resolved, by a milder temperature, into flowing water. When the seas were afterward reduced nearly or quite to their present limits, and the icebergs restricted to the frigid zones and their vicinity, streams had to make their way down the sides of the mountains and hills to the subjacent valleys and plains, sweeping along not merely sand and gravel, but bowlders also, of every size and form, and sometimes great rocks as well, by the force of their impetuous currents. And, as a very large, if not the larger portion of our earth's surface bears testimony to the existence and powerful action through ages, of larger and smaller water-courses, a wide and general diffusion of stones, not in place, but more or less triturated, smoothed, and rounded, by the action of water, was among the inevitable results. These stones are sometimes a facility, but oftener an impediment, to efficiency in agriculture. When heated by fervid sunshine throughout the day, they retain a portion of that heat through a part of the succeeding night, thereby raising the temperature of the soil, and increasing the deposit of dew on the plants there growing. When generally broken so finely as to offer no impediment to cultivation, they not merely absorb heat by day, to be given off by night, but, by rendering the soil open and porous, secure a much more extensive diffusion of air through it than would otherwise be possible. Thus do slaty soils achieve and maintain a warmth unique in their respective latitudes, so as to ripen grapes further North, and at higher elevations, than would otherwise be possible.