Description

Offered for sale we have a very collectable example of a compact antique upright monocular brass microscope with the instrument dating it to around the 1872-3 period by Ernst Gundlach (1834  – 1908).  It’s a fairly late example of Gundlach’s German production and carries serial number 1059, which dates it to just prior to Gundlach emigrating to the United States in 1872-3.  Once he’d moved to the US Gundlach worked for inter alia Bausch & Lomb as well as manufacturing instruments under his own name.  

The condition of this instrument is generally good for its 150 plus years, with only a few minor age and use appropriate signs of wear to the instrument.  It’s got a good time worn look to its brass-work, with most of the brass showing oxidation patina and no doubt quite a back story.  Being a compact upright instrument, it’s also a good proposition for display, say on a desk-top or in a home office when set up with a suitable antique slide.  It’s also perfectly usable producing some nice bright images and I’ve put a low magnification image of the antique slide I was using for testing purposes in the listing photo stream.  It’s also endowed with a good range of magnification via its current set of Seibert objectives.

This instrument is a compact upright model referenced as Model 5 in the technical literature, with production confirmed as 1870s.  The technical details for this example are as follows:

1)  Tuning-fork shaped brass foot construction with single C-shaped upright in brass to which attach both stage and upper limb.  This compact microscope is non-inclinable.

2)  A monocular eyepiece with three period top-hat style eyepieces (probably by Seibert but unbranded) as follows:

– No. I – 7.5x magnification
– No. II – 12x magnification
– No. III – 15x magnification

3)  The instrument’s coarse focus is operated via a single-sided thumb-wheel controlled rack & pinion system, with rack that’s recessed into the optical tube and in view of the instrument’s age it’s the old-style straight-cut type.  The optical tube in turn friction-fits into a brass outer tube that’s attached to the fine focus column via parallel linkage that’s similar to some Leitz instruments of this period.  Overall the coarse focus action is nice and smooth, holding position as it should in its working range.  

Fine focus is a novel design that’s very easy to use and intuitive once you’re used to the unusual placement of the fine focus thumb-wheel, in that control is via a single brass thumb-wheel to the underside of the support column. The fine focus action is also nice and smooth once one gets used to the odd location of the control.

4)  There’s three brass objective lenses all by Seibert described below:

– No. I – 7x magnification
– No. II – 10x magnification
– No. III – 40x magnification
Note: the thread for the objectives is non-RMS.

The objective lenses and eyepieces supplied therefore provide an effective magnification range of around 50x to 600x. 

5)  The stage is of a plain square design in solid brass with some signs of surface wear and patination and it’s fitted with a pair of spring steel slide clips.  

6)  Sub-stage there’s a plug-in mount to which friction-fits a variable stop accessory.  The mount also slides out to the side of the stage as shown in the listing photos.  There’s a number of different sizes of stop that can be fitted.

Lighting is provided by plano-concave mirror on a gimbal mount, with swing adjustment, silvering is good with reflectivity that’s perfectly adequate for this application.

7)  There’s a rather nice well-made hardwood storage case with fitted interior and working lock and key which is always nice to have.

In summary, this is a lovely example of a compact antique monocular microscope from the 1870s that’s in good working and decent cosmetic condition for its age.  Being compact it’s also a perfect desk-top accessory, especially when set up with an appropriate antique slide – it’s working height is about 12 inches as shown in the listing photos.  

For shipping, the instrument and case will be very well packed and dispatched by insured courier upon receipt of cleared funds.  

Thanks for looking.