Description

Offered for sale is a really nice example of an antique Carl Zeiss of Jena, Germany monocular stand 1a microscope standing on a horseshoe foot in black enamel and lacquered brass finish.  According to my Zeiss instrument dating sources, manufacture was in 1888 with the instrument carrying serial number 12793.  Examination of the Zeiss order book shows that this stand 1a was supplied to George Mason Opticians of Glasgow on 29 December 1888.  It’s also very nice to see that there’s a corresponding inscription on the main optical tube confirming that Mason were operating as Zeiss’s agents at that time.  So in terms of the initial provenance for this instrument we have:

– Manufacture by Carl Zeiss in December 1888
– Order book entry dated 29 December 1888 for George Mason Opticians of Glasgow
– George Mason & Co acting as importers and wholesalers
– Retailed in the UK by Clarkson’s Optical Stores, 338 High Holborn, London – plaque on inside of the case

The condition of this example is generally very good, with just the right age and use signs of wear to the paint finish and lacquer here and there where you’d expect for a high quality well-made piece of Victorian-era optical engineering that’s been well used and also well looked after.  This example has also got a set of good quality objective lenses and eyepieces mainly by Zeiss.  This example may well therefore be quite a sought-after classic model in view of the very high build quality, good manufacturer, optics, polarising accessories (described in full later in the listing) and general condition and completeness of the package.

Turning to the principal technical details of this quality monocular microscope, we have the following:

1)  Construction is a solid brass horseshoe foot in black enamel finish with twin uprights to the main pivot with tension adjustment and continental upper limb also in brass with black lacquer finish.  There’s a monocular eyepiece unit with brass draw-tube that’s graduated for tube length, allowing it to be set quickly at the optimum 160, 170 etc  value depending on the optics being used.  There’s quality eyepieces supplied as follows:

– 12x magnification – by Otto Seibert, der Junger e Wetzlar
– No. 6 – 15x magnification – Zeiss
(There’s also a micrometer eyepiece No. 2 – 6x magnification in the polarising accessory set)

2)  The instrument’s main focus is controlled via sets of thumb-wheels located at the top of the limb which move the main brass optical tube – travel and focus are both very good with the optical tube holding in position as it should on adjustment.  Fine focus is the continental type atop the rear pillar, with a single graduated thumb-wheel which has been cleaned and lubricated, so now also works as it should.  The upper limb on this model of microscope is designed to tilt and there’s a mechanism for locking in position as required via a tension lever.  

3)  There’s three quality objective lenses by Zeiss as follows:

6x magnification – aa
30x approx magnification – C
100x magnification – 1/12th inch – oil immersion
(the objectives all have correct brass canisters)

The objective lenses and eyepieces supplied therefore provide an effective magnification range from around 36x magnification right up to a 1,500x magnification when using the 100x objective with the highest power eyepiece along with an appropriate immersion technique and very good illumination. 

4)  The stage is fully mechanical, of a circular design with rotation and it has good level of resistance to motion so that it holds in position on adjustment.  The x and y axis controls are on the right-hand side giving a good range of smooth x/y adjustment.  The stage is fitted with a pair of sliders for holding slides steady which work well.  Note – the stage will not complete a full 360 degree rotation because of the x/y thumb-wheels.  The mechanical stage can also be swapped over for a plain stage with twin slide clips.

5)  Below stage there’s a ring mount of 37mm diameter that can accept a friction-fit condenser lens – the condenser also has its own storage rack in the case when not in use.  Below the condenser there’s an iris with centering via a horizontal rack & pinion mechanism – this also swings out of the optical path to allow access to the ring mount as shown in the listing photos.  There’s a further rack and pinion system to adjust the sub-stage height with single-sided control. 

6)  Lighting is provided by a plano-concave mirror on a gimbal mount with age-appropriate silvering to both sides with some marginal foxing but still perfectly functional.

7) Accessories supplied as follows:

– Bull’s-eye table-top condenser on brass stand with heavy lead-weighted base
– Plain circular stage in brass with twin slide clips
– Polarising equipment by Carl Zeiss in a period fitted case comprising – sub-stage nicol prism polariser, eyepiece nicol prism analyser with rotation, goniometer with degree scale and a micrometer eyepiece with integral draw-tube and internal graticule with vertical 0 to 10 scale – this eyepiece is 6x magnification

7)  There’s the correct matching-numbers hardwood case with this example which is a quality well-made piece in its own right in very good condition with lovely exterior finish and period sheen.  It’s got internal racking for accessories/objectives/eyepieces and its lock and key are present and working which is always nice to have.  It’s also very interesting to note that the key is the original Zeiss key from 1888 with the Z-logo.

In summary, this is a highly collectable example of an antique Carl Zeiss Stand 1a microscope in very good condition and well specified.  It may therefore appeal to collectors as well as specialists seeking a really well made quality instrument with monocular set-up and also polarising functionality. 

This is also quite heavy microscope equipment especially with its sold brass construction and the wooden storage case, so owing to its weight it will be partially dismantled, very well packed and dispatched by insured courier upon receipt of cleared funds. 

Thanks for looking – please check out my other listings if you get a chance.