John Bleuler (1757-1829) was an optician, mathematician, philosopher, and instrument maker who began his profession as an apprentice to Henry Shuttleworth in 1771 and 20 years later, in 1791, opened his own business at 27 Ludgate Street, London. He continued to make instruments until his death in 1829.
Excellent and elegant brass microscope of the Culpeper type with a complete collection of accessories signed on the observation base with the name and address of J. Bleuler in London, in a magnificent mahogany box. Although unusual, this one has a rack and pinion mechanism for focusing instead of the common slide system on the main tube. The microscope is accompanied by a set of original accessories in perfect condition, consisting of 4 lenses of different magnifications, a "fishplate", and a "live box" for observing live animals, tweezers, and a container for observing liquids. The original gold lacquer is excellently preserved with only minor scratches and mottling. The mirror has lost a small part of the silver and has a dent. In its minimum position it measures 25.7 cm. The mahogany box is also well preserved, retaining the original lock but not the key. It also has the upper handle and the drawer for accessories. His height is 32.3 cm.
References: "Billings Microscope Collection" pag 17, fig. 30
G. Turner, "Great Age of the Microscope", pag 64, Num catálogo 37
G. Turner, Collecting Microscopes, pag 42
Links: http://www.antique-microscopes.com/photos/culpeper_rack.htm
http://www.arsmachina.com/bleuler1381.htm