Along with this new architectural feature in the structure of the cave, there was a noticeable change in the character of the rock forming it. Walls and floor had, until now, been sharp and jagged in contour, dull, almost black, in color. But the unevenness of surface was disappearing. The rocks were smoother, as if worn and rounded by constant rubbing. Vivid colors gleamed from wall and column with a pristine freshness suggesting that this part of the cave belonged to a far more distant period than the great rock chamber in which they had stopped to take their luncheon. Finally, they were surrounded at every hand by those spear-like formations, thrust upwards from the floor or depending from the roof, that give to the interiors of most caves their fantastic appearance--the stalactites and stalagmites about whose origin in the workshop of Nature there can be no doubt. This change had an invigorating effect upon the explorers. Passing from the unrelieved gloom of the first cavern into this fairy-built grotto, with its bright hues and pleasing shapes, they began to forget their fears and felt instead something like the real enjoyment that belongs to unexpected adventure. Everything in the way of glorious surprise seemed possible. For one thing, Miranda's confident prediction was apparently about to be realized, a probability that the doctor celebrated by alternate chuckles and grunts of satisfaction. "If we don't find water, there is at least no doubt that water has once been here," declared Leighton. "These stalactites make that certain." "You will see--you will see," persisted Miranda. "It is the Lake Guatavita." "How can that be?" argued Leighton. "No opening of the lake into this cave has ever been discovered." "You will see."