You'd probably guess, if asked, that the first Mile High Club members were those dashing stunt pilots of the 1920s, who did things like play tennis on the wings of a plane. You'd be off by a century and a half. As soon as the very first woman took to the skies, people started having ideas.
Something people don't think about when they see hot air balloons now was that the people who used them in the late 1700s were the equivalent of stunt pilots crossed with celebrities. Huge crowds attended their launches, people composed poems and stories about them, bought their memoirs, and tore apart their clothes as souvenirs. Each new flight required a bigger stunt than the one before, and Vincenzo Lunardi had a big stunt cooked up. Lunardi and a daring young aeronaut named George Biggin were going to launch in London, and they were going to do so in the company of the first woman to go up into the air. She was Letitia Sage, an actress and celebrated beauty. The balloon they were going up in had a special basket. Inside was a picnic lunch, plenty of pillows, and drapes of green silk. The wall of one side of the basket was replaced by a green silk curtain. This would keep Sage from having to clamber over the rim of the basket in skirts, and it could be opened before the flight so the onlookers could see a pleasing tableaux of the three as they prepared to launch.
Complications cropped up because Lunardi never asked how much Sage weighed, but had guessed something under the two hundred pounds she publicly, and cheerfully, declared herself to be after the flight was over. (Those were the days, huh?) The basket wouldn't fly. When the basket, still mostly tethered to the ground, started dipping, Lunardi literally stepped down from the entire adventure. He stepped down a little too fast, causing the balloon to shoot upwards with the green curtain still open.
Sage didn't lose her head, despite the swaying of the basket during the ascent. She simply knelt down and re-fastened the curtain securely. Biggin steadied her. At least that was the official story. People on the ground saw something that seemed to them a great deal more suggestive. The stories were exacerbated by the fact that, when the pair finally did come down, somewhat haphazardly in a farmer's field, Sage was suffering from a strained tendon. A local student and balloon enthusiast paid for the damage to the field, picked Sage up and carried her bodily to a pub where they all got drunk.
Sage, to the end of her life, maintained that nothing untoward had happened, and Biggin never commented one way or another, but the idea sparked a revolution in thinking. From then on, balloon enthusiasts bet each other in clubs as to whether anyone dared have sex in a balloon a certain number of feet off the ground. The Mile High Club was born. Smuttily.
Top Image: Marcosleal
Second Image: Georgian London
Via The Age of Wonder and Georgian London.