Here on the right is a beautiful vertical steam engine, with balance and condensation (Wolf system), which operates for the mechanical service of the section. The steam is supplied to it by a boiler placed outside the palace, in the Park, and reaches it by means of underground pipes. Approach the balustrade; bend down a little: see along the platform, this shaft which turns constantly on itself at the rate of one hundred revolutions per minute. The machine you have before you is exclusively employed in turning it, and it sets it in motion by means of this belt which it sends to it. The other belts that you see are used to take from this shaft the force necessary to make the neighbouring machines work. This is said once and for all. In the following compartments we find other steam engines also in operation; like this one, the power is supplied to them by generators established outside the palace, in special buildings, and like this one again, it is by means of a shaft, running along the platform, that they communicate their movement to the mechanisms grouped in their vicinity.
©L'Exposition Universelle de 1867 Illustrée