4m telescope on Kitt Peak. Before advanced electronics telescopes had to have one of there main axis of rotation aligned parallel with the spin axis of the earth to prevent the rotation of images as they were tracked across the sky so large supports like these were needed to hold the telescope at odd angles.
The smooth surface that my hand is on is where the telescope is turned by only a half horse power motor (the bearings and weight balance of the telescope are that good). :)
This telescope use to use photographic plates and a person would "ride" in a cage at the bottom of the telescope during the night to change out the plates.
