This instrument made by Jan Paauw Jr. of Leiden (c. 1760) consists of a sliding body tube of cardboard covered in light green (inner tube) and black (outer tube) shagreen. Coarse focus is accomplished by moving the support pillar and microscope body by hand. Fine focusing is done with the Hevelius fine adjustment (mounted on the back of the pillar) after fixing the jam screw. To permit inclination of the instrument, the pillar is hinged near the oval, brass plate. The base plate is 6.3x9cm, is engraved Jan Paauw Jr. fecit, and has a mounting hole in the front. In all likelihood, it came mounted on an oval, wooden base (three nearly identical microscopes by Paauw in the Boerhaave Collection all are mounted on such bases). The Billings Collection also has a Paauw microscope (AFIP 518907), which is unmounted and similar to this instrument. This Golub Collection microscope is 29cm in height.

Optics consist of three lenses: eyepiece, field, and objective. The field lens is mounted within the brass body support. The objective as shown is an integral part of the Lieberkuhn reflector. This microscope probably came originally with five objective or six lenses plus two Lieberkuhn lenses. Only one Lieberkuhn lens remains with this instrument. The eye-piece and base of the body tube are of dark brown horn. Samples are mounted using a Bonanni spring stage. The dual-sided illuminating mirror is attached to the main support pillar via a hinged mount that allows it to be tilted and rotated. Focal lengths of the three lenses in this particular instrument are mismatched, thus imaging through the microscope is impossible.

Jan Paauw, Jr. (c.1723-1803) was a skilled instrument maker in Leiden, Holland. He constructed clocks, thermometers, pyrometers, pumps, and microscopes from 1758 until his death, and sold these instruments to the Universities of Leiden, Utrecht and Franeker, as well as the Teyler's Foundation in Haarlem. Paauw made a variety of microscopes. Many of them, including this one in the Golub collection, were nearly identical copies of the "Single and Double Microscope" microscope described in George Adams's Micrographia Illustrata of 1771*. Unfortunately, Adams ascribed no maker to this microscope. Paauw also was an admirer of John Cuff instruments, stating that he considered the Cuff microscope to "be the best microscope suited to many purposes".

Paauw was highly educated, having received a Ph.D. in 1762 from the University of Franeker, and was prominent among Dutch scholars. He constructed instruments for other prominent makers at that time, including P. van Musschenbroek. In 1800 Jan Paauw was appointed superintendent of instruments at the Theatrum Physicum in Leiden. The inventory in Paauw's workshop including 10 microscope lots, was sold at auction in 1804.

*George Adams. 1771. Micrographia Illustrata, or the Microscope Explained in Several New Inventions. 4th Ed London. George Adams, Mathematical Instrument Maker to His Majesty George the IIId. Figure 16, Plate 10, Front page 34.