As far as i recall it is because the mixture and type of gases they attempted to use were more or less futile to sustain a air balloon to successfully travel and a medium rate of speed, and were over-encumbering and heavy.
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The lawyer despairs of life, and he reneges on the wager with banker
Answer:
1 : to become dry and sapless especially : to shrivel from or as if from loss of bodily moisture.
2 : to lose vitality, force, or freshness public support for the bill is withering.