About four o’clock
`` You may explain the matter as you like , '' continued Joe , `` it 's a strange thing , anyhow ! '' But ere long this picture began to fade away ; the clouds rose higher , leaving the balloon , which made no further attempt to follow them , and in about an hour they disappeared in the open sky . The wind , which had been scarcely perceptible , seemed still to diminish , and the doctor in perfect desperation descended toward the ground , and all three of the travellers , whom the incident just recorded had , for a few moments , diverted from their anxieties , relapsed into gloomy meditation , sweltering the while beneath the scorching heat . About four o'clock , Joe descried some object standing out against the vast background of sand , and soon was able to declare positively that there were two palm-trees at no great distance . `` Palm-trees ! '' exclaimed Ferguson ; `` why , then there 's a spring -- a well ! '' He took up his glass and satisfied himself that Joe 's eyes had not been mistaken .