The wind blowing against the opening, which faces it, charges the ballonet with air.
The air pump, which should have pumped the ballonet full of air to keep the balloon rigid failed to work.
The magneto was run by a belt from one of the ballonet blowers.
(p. 067) The balloon frame was divided into seventeen compartments, each of which held a ballonet filled with hydrogen gas.
Special features is a "belly" of Para rubber in lieu of a ballonet.
There are two noteworthy innovations in connection with the ballonet.
It had an internal air-bag or ballonet whose capacity was one-fifth that of the envelope.
ballonet, filled by a separate motor giving 7.5 inches of water pressure.
It appears to be rearing up on end, as if the extremity saddled with the ballonet were weighted.