The guide being anxious that we should not fail to see the Niagara Room, we now turned toward a low, broad opening in the wall, a short distance to the right of the entrance, where the rising floor and descending ceiling, failing to meet, had overlapped; so we made our way up a steep, smooth bank, and then down on the other side over a broken, rocky surface for a distance of about twenty feet, when the roof at last joined the floor and two small water-worn holes at the point of junction revealed an untempting passage within. The broader of these holes was three feet, but too low to be considered an entrance; the other was round but certainly not so large as our guide, who was preparing to enter it with doubts of his ability to make the trip, on account of having increased in size since his one entrance there, on which occasion two smaller guides pulled him through the tightest places. Carefully comparing his size with that of the hole he sat beside, there was no possibility of doubt that if the attempt were made he would stick fast, and that would place our little party in dire straits. Consequently I insisted that it should not be, but he was unwilling that Niagara should be missed when so near. Finally I positively refused to go unless he would consent to give us instructions and remain where he was while we went without him, to which he at last yielded with extreme unwillingness. He had frequently shown us the guide's marks, and now earnestly cautioned me to advance only as they point, and turn back if they should fail. The small nephew went on a reconnoitering expedition to the end of the passage, and reported that the jump-off there was higher than himself but he could get down. I now crawled through the hole and found the passage to be a "crawl" or rather a "sprawl," from fifteen to eighteen inches high, but having an ample width varying from three to six feet. The smooth, straight floor has a steep downward inclination and is thickly covered with dust.