Description

Offered for sale is a really nice example of an antique Ernst Leitz of Wetzlar, Germany monocular laboratory-grade microscope known as the Universal model standing on a horseshoe foot in black enamel finish – dating to around 1919 and carrying serial number 186495.  Checking my copy of the Leitz dating table indicates manufacture in the period just as WWI was coming to a conclusion, so 1918 to 1919, which would have no doubt been a turbulent time in Germany.

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 and a look that belies its true age.  This example has also got rather nice quality objective lenses by optical firm R. Winkell of Gottingen, which by 1919 was part-owned by Carl Zeiss.  This example may well therefore be quite a sought-after classic model in view of the quality build, good manufacturer, optics 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 single upright to the main pivot with tension adjustment and Lister-type 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 a very good comprehensive collection of eyepieces supplied as follows:

– No. 0 by Ernst Leitz – 4x
– No. 1 by Ernst Leitz – 5x
– No. II unbranded – 6x
– No. 4 Compens Okular by Carl Zeiss – 10x
– C. Baker, London – 15x

2)  The instrument’s main focus and fine focus are 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.  Fine focus 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 tension lever for locking in position which works well.  

3)  There’s a good selection of quality objective lenses on a triple turret, with objectives as follows:

3x – R. Winkell 40mm apochromatic – low power and very high working distance
15x – R. Winkell 13mm fluorite
20x – R. Winkell 8.5mm fluorite
100x – R. Winkell 1/12th inch – oil immersion
(the objectives all have brass canisters)

The objective lenses and eyepieces supplied therefore provide an effective magnification range from around 12x magnification right up to a theoretical 1,500x magnification when using the 100x objective with the highest power eyepiece along with an appropriate immersion technique and good illumination. 

4)  The stage is of a circular fully mechanical design with rotation and it has good level of resistance to motion so that it holds in position and can be centered via thumb-screw adjusters.  There are x/y thumb-wheel adjusters on the right hand side of the stage which work well.  The mechanical stage is however missing its slide holder arms that locate in a dovetail recess and while y-axis movement can be controlled via the adjustment thumb-screw.  In view of the missing slide holder arms, a specimen slide sometimes has to be moved manually along the x-axis.  The mechanical stage also has vernier scales for both axes and a locking mechanism to prevent the y-axis slipping on inclination, which is a nice feature to have. 

5)  Below stage there’s a complex condenser arrangement by Leitz, with smoothly operating iris and swing-out feature shown in listing photos.  The condenser lens assembly can be fully swung out of the optical path for low power work, which then brings the top iris into play.  Below the condenser is another iris with centering via a horizontal rack & pinion mechanism – the adjustment thumb-screw has to be tilted upwards slightly to engage the rack mechanism.  There’s a further rack and pinion system to adjust the height with single-sided control.  All in all a versatile sub-stage arrangement, that can also be fitted with a filter – I was using a 32mm blue opaque filter as you may be able to see in the listing photos.

6)  Lighting is provided by a plano-concave mirror on a gimbal mount with very good silvering to both sides.

7)  There is a later (1950s) hardwood case which is a quality well-made piece in its own right in good condition.  It’s got internal racking for objectives/eyepieces, a large sundries drawer and its lock and key are present and working which is always nice to have. 

In summary, this is a highly collectable example of a large antique Leitz Universal model microscope in good condition, with a couple of minor issues as noted in the listing text.  This example may therefore appeal to collectors as well as specialists seeking a really well made quality instrument with monocular set-up. 

This is also quite heavy laboratory microscope equipment especially with its sold brass construction and the large 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.