EXHIBITS > Measuring instruments, tools and machines of the ancient Greeks >
The windpowered ''hydraulis'' (organ)
This is the first substantial use of wind powering a machine worldwide. It consisted of the disposition of windpowering and a hydraulis. The disposition of windpowering consisted of a horizontal axis which at one end had a vertical windwheel and on the other side had a wheel with rods. The axis was based on an iron benchframe encased in a movable platform (which was directed towards the wind). One (articulated at the middle) horizontal bar was flattened at one end while the other end was articulatedly connected with the axis of the piston of the hydraulis cylinder. With the energy of the wind the windwheel rotated and the rods hit the flattened end of the bar and descended, successively. Therefore, the hydraulis piston lifted and each time descended again because of its weight. Thus, the hydraulis was supplied with the required air for its operation.
SOURCES: "Heron of Alexandria, Pneumatica"