I found an article in an old French technical magazine La Nature from 1897 about a tin toy made by Martin.
This special piece is put in motion by stretching both sides of the cord, the air cyclist goes up and down when the cord is relaxed, the cyclist descends.
It was first made in 1897
length approx 16cm (6.3 inch)
Martin article number is 156
Free translation: The aerial unicycle.
The toy in question represents a unicyclist who climbs along a string that can be seen at the upper part and at the lower part of our drawing (n. 1 Detail view). It is easy to understand the mechanism that elevates the little climber.
Inside the wheel is a pulley movable around its center and on which winds the string.
This one penetrated into the wheel passing through a small ring carried by the handlebars.
By exerting a slight traction on the rope, as shown in (n. 2 Instructions for use) of the figure, the movement of the apparatus is obtained.
The internal pulley carries an axis on which a pedal is fixed which can be seen.
The cyclist rests his feet on it, and since the legs are articulated, the toy offers the funny image of a cyclist maneuvering the pedals.
The aerial unicycle is at the same address as the spider and the fly.