Description

Watson Bactil Monocular – circa 1934 in Lacquered Brass Finish

Offered for sale is a superbly engineered vintage original Bactil model microscope by W. Watson & Sons Limited of London.  It dates to 1934 based on the sequential Watson production number of 53377, which is engraved onto the main optical 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 a nice period storage case.  It presents really well with very few 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 glow 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 91 years old, so almost an antique. This is a sturdy good quality microscope in original condition, fully working, with no significant signs of wear that I can find, so it’s got a great look and patina and a great brass example from the mid 1930s.  

On the technical side, the construction is a heavy iron foot, with twin uprights, pivot and Lister-type upper limb also in iron.  Both coarse and fine focus move freely through their working ranges with little wear evident.

Turning to the optics, this Watson Bactil microscope comes fitted with a period graduated brass eyepiece draw-tube and optical tube in brass.  There’s an appropriate quality vintage Watson eyepiece that with good illumination produces excellent images:

– 10x magnification 

There are three vintage Watson objectives and another unbranded low power one, along with a triple brass turret, which rotates freely with a positive feel as the objectives slot into position.  The objectives are as follows:

– approx 1.5 inches – 4x magnification – unbranded brass objective
– 2/3rds inch – Watson Parachromatic -10x 
– 1/6th inch – Watson Parachromatic – 40x 
– 1/12th inch – Watson Versalic oil immersion required – 100x 
(All Watson objectives have correct period canisters)

Overall, the range of magnification provided by this Watson Bactil therefore ranges from about 40x to a perfectly respectable 1,000x when using oil immersion techniques.

The mechanical 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 x/y controls also offering fine control of specimen positioning which is a must for higher magnification work.  The y-axis also holds position on inclination.  The mechanical stage can be removed by winding the y-axis forward to the end of the rack, then manually pulling it off the dovetails.  It can then be substituted for the over-size plain stage as demonstrated in the listing photos.  The plain stage is currently missing its slide clips and I will endeavour to source a suitable pair of clips and add to the listing when I can.

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 twin-sided height control and there’s also centering.  It’s also reassuring to note that the condenser has adequate vertical reach for oiling to the back of a slide as may be required for higher magnification applications.  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 Watson’s Bactil model in brass with excellent originality, making it quite an interesting proposition for a collector.  It’s in highly original unmolested condition with a good specification, nice optics and it’s essentially a very collectable brass example.  

There’s also a later wooden case with working lock and key, which is also in decent condition and it’s interesting to note that the original Watson guarantee card is attached to the inside of the case door, which confirm that date of manufacture as 2nd August 1934.

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.