regarding air balloons, i did wonder, but got mis directed by trans atlantic wiki, where the mention for flight had blimp style in reference, so in my mind, flight was either plane or blimp style, and completely forgot that balloons existed. still, i do not know if it was cost effective to do aerial surveys, as i do not know what would have been the best nergy source available back then, coal i guess, and maybe some other liquid hydrocarbons (we have been doing liquid fuel for some time i think, but it would definitely be dirty).
Might just be wood or other organic materials - I know some of the earliest hot air balloons just burned material on the ground, filled up with hot air, and then would float until they ‘ran out’.
thank you for the answers.
regarding air balloons, i did wonder, but got mis directed by trans atlantic wiki, where the mention for flight had blimp style in reference, so in my mind, flight was either plane or blimp style, and completely forgot that balloons existed. still, i do not know if it was cost effective to do aerial surveys, as i do not know what would have been the best nergy source available back then, coal i guess, and maybe some other liquid hydrocarbons (we have been doing liquid fuel for some time i think, but it would definitely be dirty).
Might just be wood or other organic materials - I know some of the earliest hot air balloons just burned material on the ground, filled up with hot air, and then would float until they ‘ran out’.