This is a wonderful original 1800’s all brass microscope.  Measures 13″, there are no manufactor’s  markings on the item.  The microscope date backs to the 1600’s and some even claim earlier 1200;s 

The first detailed account of the interior construction of living tissue based on the use of a microscope did not appear until 1644, in Giambattista Odierna’s L’occhio della mosca, or The Fly’s Eye