four o’clock in the
morning
To-morrow , my friends , should the wind prove favorable , we shall go due north , and we shall , perhaps , discover the sources of the Nile , that grand secret which has so long remained impenetrable . Near as we are to the sources of the renowned river , I could not sleep . '' Kennedy and Joe , whom scientific speculations failed to disturb to that extent , were not long in falling into sound slumber , while the doctor held his post . On Wednesday , April 23d , the balloon started at four o'clock in the morning , with a grayish sky overhead ; night was slow in quitting the surface of the lake , which was enveloped in a dense fog , but presently a violent breeze scattered all the mists , and , after the balloon had been swung to and fro for a moment , in opposite directions , it at length veered in a straight line toward the north . Dr. Ferguson fairly clapped his hands for joy . `` We are on the right track ! '' he exclaimed .