CHAPTER TENTH.
Former Experiments.—The Doctor’s Five Receptacles.—The Gas Cylinder.—The Calorifere.—The System of Manœuvring.—Success certain.
“The attempt has often been made, gentlemen,” said the doctor, “to rise and descend at will, without losing ballast or gas from the balloon. A French aëronaut, M. Meunier, tried to accomplish this by compressing air in an inner receptacle. A Belgian, Dr. Van Hecke, by means of wings and paddles, obtained a vertical power that would have sufficed in most cases, but the practical results secured from these experiments have been insignificant.
“I therefore resolved to go about the thing more directly; so, at the start, I dispensed with ballast altogether, excepting as a provision for cases of special emergency, such as the breakage of my apparatus,
