Nuremberg Microscope (c.1770)
Nice microscope made in Nuremberg Germany by the toy manufacturers of the region. They are made of wood with decorated cardboard tubes. Specimens were produced especially during the 18th century and until the beginning of the 19th. Several styles designed to mimic some of the brass microscopes of the day were made, basically copying the so-called "drum" and Culpeper models. In this case, the microscope is of the "drum" type but the base is rectangular to simplify construction. Frequently, the bases of these microscopes were marked with the manufacturer's initials. The manufacturer of this microscope, IM, is well known for having copies of his in different museums.
These microscopes were produced in large numbers in Nuremberg and other parts of southern Germany during the first half of the 18th century. Their basic design and simplicity led to their being called Nuremberg "toy" microscopes, and they were often displayed at the many toy fairs held in this region. The microscope is constructed of a set of sliding, turned wood tubes with biconvex lenses that serve as the eyepiece, tube lens, and objective. A simple eyepiece and single objective lens allowed for modest magnifications with significant optical aberration. Focusing can be achieved by sliding one tube into another to change the distance between the tube and the lens of the eye. Slots in the rectangular base allow large slides to be placed in the field of view. A biconcave mirror serves to reflect ambient light into the optical tube.
References: "Billings Microscope Collection" pag 10, fig. 19
Links: http://www.antique-microscopes.com/photos/Nuremberg.htm
https://golubcollection.berkeley.edu/18th/60.html