Watt wrote to Dr Joseph Black in 1783 that “The Whole World is Full of these Flying Balls at present”.
In August 1783 the Frenchman J A C Charles and two brothers called Robert substituted hydrogen, or“inflammable air”, for hot air. Alarmed locals pitchforked their balloon where it landed.
They went up
And up even more.
Before touching ground again on the property of an interested landowner who was intrigued by his sudden visitors arriving in such a novel manner.
Robert hopped out to explain what they were up to, whereupon the balloon took off again with Charles still aboard. This time he was taken so high he had an almost religious experience (probably along the lines of “I swear if I get down from up here in one piece, I’ll never do it again”).
The balloon and its pilot were loaded on to a wagon and returned to Paris, closing a dramatic chapter in the early history of aeronautics.
Watt’s partner Matthew Boulton experimented with thin copper, along the way managing to make one of his test balloons explode in mid air.
It wasn’t really their thing, and Watt wrote to another friend in October 1794
“Mr Boulton did idle a great deal of his time in playing with some small balloons some time ago but I hope he is now cured of the balloonomania” .