about ten o’clock in
the morning
Perhaps , too , while retaining the water , he might have ascended by throwing out ballast , at the cost merely of discharging some gas , when he had again to descend . But the gas in his balloon was his blood , his very life ! A thousand one such reflections whirled in succession through his brain ; and , resting his head between his hands , he sat there for hours without raising it . `` We must make one final effort , '' he said , at last , about ten o'clock in the morning . `` We must endeavor , just once more , to find an atmospheric current to bear us away from here , and , to that end , must risk our last resources . '' Therefore , while his companions slept , the doctor raised the hydrogen in the balloon to an elevated temperature , and the huge globe , filling out by the dilation of the gas , rose straight up in the perpendicular rays of the sun . The doctor searched vainly for a breath of wind , from the height of one hundred feet to that of five miles ; his starting-point remained fatally right below him , and absolute calm seemed to reign , up to the extreme limits of the breathing atmosphere .