eleven o'clock
Pure hydrogen prepared according to the method of the celebrated Henry Gifford filled the enormous balloon . And as the capacity of the `` Go-Ahead '' was 40,000 cubic meters , the ascensional power of the gas she contained was 40,000 multiplied by 1,100 or 44,000 kilograms . On this 29th of April everything was ready . Since eleven o'clock the enormous aerostat had been floating a few feet from the ground ready to rise in mid-air . It was splendid weather and seemed to have been made specially for the experiment , although if the breeze had been stronger the results might have been more conclusive . There had never been any doubt that a balloon could be guided in a calm atmosphere ; but to guide it when the atmosphere is in motion is quite another thing ; and it is under such circumstances that the experiment should be tried . But there was no wind today , nor any sign of any .