Description

Watson Bactil Monocular – circa 1927 in Brass with matching numbers storage case

Offered for sale is a superbly engineered vintage original Bactil model microscope by W. Watson & Sons Limited of London.  It dates to 1927 based on the sequential Watson production number of 38581, which is engraved onto the main optical tube.  This example was originally retailed by Watson sales agent Baird & Tatlock of London, with an engraving to this effect also on the main tube.

This inter-war example is in all-original condition as far as I can tell and has clearly been really well looked after by its former custodians. This Bactil also benefits from a good set of original period-correct lenses, an original brass mechanical over-stage and correct period storage case.  It presents really well with virtually no age-related blemishes anywhere on the instrument and lovely gleaming brass-work throughout.  The brass-work really catches the sun and glints with a lovely warm yellow/golden hue as I hope the listing photos demonstrate.  

The Bactil is essentially an excellent piece of British optical engineering built from quality materials, with solid construction, great design and skilled workmanship and in this period many hours of hand-finishing and it’s hard to believe that it’s actually 98 years old, so almost an antique. This is a sturdy good quality microscope in original condition, fully working, with no signs of wear that I can find, so it’s got a great look and patina and just about the best brass example from the mid 1920s you could hope to find.  

On the technical side, the construction is a heavy iron foot, with twin uprights, pivot with tension adjustment, which works well and Lister-type upper limb also in iron.  Both coarse and fine focus move nice and freely with little wear evident.

Turning to the optics, this Watson Bactil microscope comes fitted with a period graduated brass eyepiece draw-tube and extra-wide optical tube in brass.  There are some appropriate quality vintage Watson eyepieces that with good illumination produce excellent images:

– 6x magnification
– 10x magnification 

There are also some later eyepieces – 8x magnification by CTS and a wide-field 10x by Vickers Instruments, giving a nice selection of optics.

There are three vintage Watson objectives and a low-power objective by W R Prior along with a triple brass turret, which rotates freely with a positive feel as the objectives slot into position.  The objectives are as follows:

– 1.5 inch low-power by W R Prior – 3.5x magnification
– 2/3rds inch – Watson Parachromatic -10x 
– 1/6th inch – Watson Parachromatic – 40x 
– 1/12th inch – Watson Versalic oil immersion required – 100x 
(All objectives have correct period canisters)

Overall, the range of magnification provided by this Watson Bactil therefore ranges from about 22x to a perfectly respectable 1,000x when using oil immersion techniques.

The mechanical over-stage is an original Watson factory-fitted item in brass with two armatures one of which is sprung.  This system is excellent for retaining slides during inclined viewing, with freely running x/y controls also offering fine control of specimen positioning. The over-stage locates to the standard Watson ebonite stage via two slender bolts that fit through the holes where stage clips normally reside.  The over-stage is tightened into position from below via two small brass thumb-screws and overall, the system works very well.

Turning to the sub-stage, we have a Watson Abbe-style condenser in a brass ring-mount, which sits in a height adjustable rack and pinion system with single-sided height control, swing-out feature as demonstrated and there’s also centering.  It’s also reassuring to note that the condenser has adequate vertical reach.  There’s a working iris to control lighting levels and lighting and a swing-out filter carrier.  Lighting is via a plano-concave mirror which is in very good condition on its adjustable brass support rod and gimbal set-up with excellent silvering to both sides.

This is a great visual and excellent working example of a fairly early Watson Bactil model in brass with excellent originality, making it quite an interesting proposition for a collector.  It’s in highly original condition with a comprehensive specification, good optics and it’s essentially very collectable.  There is also the period-correct “matching numbers” storage case with this example, which is also in very good condition with an internal storage racking for the lenses/eyepieces, a sundries drawer and also an original working lock with key.

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

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