The higher you are, the farther you can see.
So ...
collect information about a battlefield
and
spot the gunnery results.
Hot air balloons were used for reconnaissance during the civil war.
no
The first use of hot air balloons was in the American Civil War for surveillance of troop movements.
bbksu
telegraphs hot air balloons spies/couriers telegraphs hot air balloons spies/couriers
Hot air balloons
The Civil war
To spy on the enemy
Hot air balloons
Hot air balloons
the civil war of which country?
They were used for reconnaissance of troops in the civil war. They were the first type of "spy" from the air.