Dating carl zeiss microscopes
Carl Zeiss of Germany is among the most renowned of the lens manufacturers.
It's part of the Carl Zeiss Foundation, which also owned the Zeiss Ikon camera maker from its foundation in 1926 until it disappeared in 1972.
Then, during the 1590's, two Dutch spectacle makers, Zacharias Jansen and his father Hans started experimenting with these lenses.
Their first microscopes were more of a novelty than a scientific tool since maximum magnification was only around 9x and the images were somewhat blurry.
Although no Jansen microscopes survived, an instrument made for Dutch royalty was described as being composed of "3 sliding tubes, measuring 18 inches long when fully extended, and two inches in diameter".
In its long history it equipped many camera makers.
The company was founded in Jena in 1856 and called Carl Zeiss Jena. In 1909 the camera making daughter company was merged into the ICA group which later became part of Zeiss Ikon.