Microscope This is a metal monocular microscope, black coloured. It features a U-shaped heavy base for stability, connected to a tube (called the arm) in which the microscope's components are securely screwed in. The illuminator, a circular mirror that rotates, is attached to the base. On top of it, there is a square metal piece with a round hole in the middle (called the stage), and a rotating plate beneath it, which features holes of different sizes to allow a regulated amount of reflected light to come in (called the aperture). On the top side of the stage, two adjustable flaps (called stage clips) can be loosened by twisting the screws; this would have allowed positioning of the microscopic glass. The stage is engraved with a millimetre scale and a sliding mechanism which operates thanks to the screw on the side, to better observe the microscope glass slide that would sit on the stage and be placed on top of the stage fenestration. The final mounted piece is the eyepiece holder. The eyepiece is removable and adjustable by twisting its position in the holder, and consists of a long tube featuring lenses on both ends. Additionally, there is a rotating component at the end of the arm featuring two of the three zoom/focuses, one engraved with "Hi 90" and the other "Hi 40". The microscope is engraved with "Carl Zeiss Jena Nr 251312". This type of microscope was used for various purposes, such as studying cells, tissues, and microorganisms; examining blood samples, tissues, and other biological specimen 1900-1949