Dick stooped and dipped his hand in the water, which reached to their very feet. “Well, this is worth seeing!” he declared. “This was constructed by Constantine more than fifteen hundred years ago,” explained the professor. “Think, boys, what you now behold is the work of man, yet it remains practically the same as when constructed fifteen centuries ago.” “It looks like a partly submerged cathedral,” murmured Dick. “One can fancy all its worshipers and priests as drowned in that flood of black water. In fancy I seem to see their restless spirits floating above the surface of the lake, away, away yonder in the unknown distance. How large is it, professor?” “There are three hundred and thirty-six of those marble columns, arranged in twenty-eight rows. I fancy the real reason why Mustapha refused to enter here is because of the many legends and tales told concerning the place. It is said that these vaults often echo to hollow laughter, and that the place is haunted by the ghosts of murdered sultans of past ages, whose places were usurped by the very monsters who intrigued to bring about the murders. Some claim that the spirits of the beautiful women destroyed by jealous sultans are doomed to float forever here above the surface of this buried lake, and that occasionally one of them is seen by a visitor for a single fleeting instant, then goes wailing and sobbing into the black distance.” “Well, by the great horn spoon, I don’t know that I blame Mustapha for not coming here!” exclaimed Brad. “It’s the most spooky old hole I ever struck.” At this juncture Bayazid inquired if they wished to take a boat and venture out a short distance on the water. “Certainly,” answered Dick, at once. “I think it will be a novel experience, and I want to go. If Brad does not——” “Hold on, pard!” cried the Texan. “Wherever you go I go, you bet your boots! Mebbe I don’t like it a heap, but I’m with you.” Bayazid left them and moved a short distance to the right. They watched him and saw the light of his torch fall on a black boat that lay motionless at the edge of the black lake. He stepped into the boat and soon brought it to the shore at their feet. Dick and Brad followed the professor into the boat, which was large enough to accommodate two more persons, if the party had included them. Bayazid had placed his torch in a socket that seemed arranged for it. He suggested that the others should extinguish theirs, as too much light close at hand would blind them, instead of making it possible for them to see better. They accepted his suggestion, and slowly the boat slipped out upon the bosom of the soundless lake. Suddenly there was a whirring rush through the air, and something brushed past the head of the professor, who uttered a squawk of alarm, struck out wildly with both hands and fell over backward off his seat to flounder in the bottom of the boat. “Howling tornadoes!” gasped Buckhart. “Whatever was that?” “A bat, effendi,” answered Bayazid.