There are many springs in Florida of this character, large underground streams that have breathing-holes, as it were, here and there. In some places the water rises and fills the bottoms of deep bowl-shaped depressions; in other localities it is reached through round natural well-holes; a bucket is let down by a rope, and if it becomes detached is quickly swept away by the current. Some of the Florida springs are perhaps the largest in the world, affording room and depth enough for steamboats to move and turn in them. Green Cove Spring is said to be like a waterfall reversed; a cataract rushing upward through a transparent liquid instead of leaping downward through the air. There are one or two of these enormous springs also in northern Mississippi,--springs so large that it seems as if the whole continent must nurse them. The Valley of the Shenandoah is remarkable for its large springs. The town of Winchester, a town of several thousand inhabitants, is abundantly supplied with water from a single spring that issues on higher ground near by. Several other springs in the vicinity afford rare mill-power. At Harrisonburg, a county town farther up the valley, I was attracted by a low ornamental dome resting upon a circle of columns, on the edge of the square that contained the court-house, and was surprised to find that it gave shelter to an immense spring. This spring was also capable of watering the town or several towns; stone steps led down to it at the bottom of a large stone basin. There was a pretty constant string of pails to and from it. Aristotle called certain springs of his country "cements of society," because the young people so frequently met there and sang and conversed; and I have little doubt this spring is of like social importance. There is a famous spring at San Antonio, Texas, which is described by that excellent traveler, Frederick Law Olmsted. "The whole river," he says, "gushes up in one sparkling burst from the earth, with all the accessories of smaller springs,--moss, pebbles, foliage, seclusion, etc. Its effect is overpowering. It is beyond your possible conception of a spring." Of like copiousness and splendor is the Caledonia spring, or springs, in western New York. They give birth to a white-pebbled, transparent stream, several rods wide and two or three feet deep, that flows eighty barrels of water per second, and is alive with trout. The trout are fat and gamy even in winter.