Description

Offered for sale is a collectable vintage Service microscope by W. Watson & Sons Limited of London.  It’s a specialist model, being the Metallurgical variant of Watson’s popular Service model, designed specifically for incident light microscopy and the study of surface features on solid/opaque specimens such as metallic surfaces.  This example dates to around 1936 based on the sequential Watson production number of 60417 which is engraved onto the main tube.  It appears to be in original condition as far as I can tell and is a nice inter-war example of this rare Service variant.  It has been both well used and looked after by its former custodians the latter of which was a metallurgist at a Glasgow Technical College.  This is therefore a good opportunity to acquire a Service model with some interesting features, more of which later in the listing.

The Service model was the mid-size model of Watson’s range of microscope offerings and the back-bone of its microscope range, first appearing in the Watson catalogue around 1919 and remaining in production right up until the late 1960s – first as the Service (this example), then Service I Research and Service II Student’s model (these both had a more streamlined shape) and then finally the Watson Barnet Service.  So, this model essentially had quite a long production run of nearly 50 years – initially in brass like this example, them from from the late 1940s onwards in chrome finish.  This long production run giving us a firm steer about how capable this model of microscope was in its heyday, so much so that this model often found its way into industrial settings, hospitals and educational establishments and this example is no exception to that general rule.

This example also benefits from a set of original period lenses and it’s also got brass-work such as thumb-wheels which are showing natural signs of age and use-related tarnishing and the instrument has in general cleaned up fairly well, with just the right patina for an example from this period and usage profile.  The Service is essentially an excellent piece of British quality optical engineering showing its quality in every component, based on the right materials, solid construction and great design.  Feel the weight of it for one, despite being a mid-size vintage microscope it’s still quite heavy with all that steel and brass.

Turning to the technical details.  For the optics, this Watson is fitted with a chromed eyepiece draw-tube with graduation markings.  The main tube is in brass with coarse focus via rack and pinion with a nice smooth action, with the main tube holding in position as it should.  Fine focus is a horizontal vernier screw/cam arrangement acting against sprung resistance which has been cleaned and lubricated and now works well. 

With this being a specialist Service variant for metallurgy, there’s a Watson vertical illuminator fitted to the main tube.  This being advanced research-grade Watson-Conrady Condenser Vertical Illuminator – see listing photos for full details.  It comprises a lamp-house with bulb-carrier and cable with working 12V 5W tungsten bulb for sample illumination.  The illuminator contains two internal irises with smooth action, condensing lens and reflector (with adjustment) to direct the light down through the objective lens and onto the sample.  Light is then reflected off the sample surface and back up through the objective and into the eyepiece for inspection.  You’ll see at the end of the listing photos that for testing purposes I was using the instrument to examine the surface features of the gold contacts on a SIM card.  I was using a Swift 12V 100W AC power supply unit to power the illuminator which gave adequate illumination – this power supply unit is also included in the listing if required, just confirm with seller when ordering.

The instrument is supplied with an appropriate vintage 10x magnification eyepiece by Watson.  It’s also got three vintage objectives including specialist metallurgical lenses all by Watson and a triple turret which rotates freely with a positive feel as the objectives slot into their viewing positions.  The objectives supplied are as follows:

– 2/3rds inch Para – Watson -10x
– 1/4th inch for metallurgy – Watson – 25x (with 15mm parfocal extender)
– 1/6th inch for metallurgy – Watson – 40x (with 15mm parfocal extender)

Overall, the range of magnification provided by this metallurgical Watson therefore runs from about 100x to around 400x.  The parfocal extenders are fitted so that only minor re-focusing is required upon switching between objectives.

The instrument tilts for inclined viewing, holding in position as it should and can be tightened via a limb tension lever on the RHS of the main pivot.  The stage is a standard Watson solid ebonite stage for metallurgy that’s fitted with a couple of stage clips, which are fine for holding samples steady.  The stage has height adjustment via rack and pinion with two-sided thumb-wheel adjustment.  The stage is therefore in theory able to accommodate samples of different thicknesses up to around 3 or 4cm, for inspection via incident illumination.

This being a metallurgical instrument, there’s no technical sub-stage.  There’s also no case with the instrument at present.

Owing to the weight and delicacy of this vintage metallurgical microscope, it will be partially dismantled, very well wrapped for shipping and dispatched by insured courier upon receipt of cleared funds. 

Please study the photos as they also form part of the description.