This is also a free balloon, but carries no meteorological instruments.
The free balloon also has a grapnel or anchor for use in landing.
For an hour or two people were surprised at seeing a free balloon sailing away towards Bulwan.
Moreover, the free balloon was subject to the whims of the breezes.
A free balloon, moving in the profound silence of the upper air, becomes an admirable sound observatory.
Deriving its power of sustentation from the gas contained in the gas-bag, the free balloon is spherical in form.
A free balloon is completely at the mercy of the wind, and simply drifts where the wind takes it.
Suppose a free balloon drifting down the wind to have a sail suddenly hoisted on one side, what happens?