Compound microscope

This cylindrical microscope tube has a consistent diameter and houses the eyepiece at the top and the lens at the bottom, with a turret-style accessory that can be used to swap between 2 lenses. Coarse focusing is achieved by the tube sliding under friction inside a drum held by an arm extending from the pillar. Fine focusing is enabled by a millimetric screw at the top of the pillar. Between the pillar and pedestal is a black stage with 2 clips on its surface and a round central hole. On the underside of the stage is a rotating diaphragm with holes of various diameters used to control light intensity. The plano-concave mirror is held by an arm, giving it a wide range of movement. The horseshoe-shaped base has quadrangular limbs but no heel. The right-hand limb bears the manufacturer's inscription: "Carl Zeiss, Jena. 8408."

Carl Zeiss (1816–88) was born in the city of Weimar but settled in Jena in 1846 and started his first business, which quickly became popular. In 1866 he began working with Ernst Abbe (1840–1905), a professor at the University of Jena, with whom he made great advances and improvements in optical systems. The 2 men became business partners in 1875 and the Zeiss factory began making much more powerful and impressive models. It improved production quality, reduced costs, and annihilated the competition to become one of the leading microscope manufacturers of the period.