Here we have a nice complete and well-equipped example of a J Swift & Son polarising monocular microscope. This example will date to around the 1960s and it bears serial number 24286. It's in excellent almost stunning original condition, easily achieving extinction when the polarisers are crossed and probably one for the collector or amateur user requiring polarising functionality.
Please read on if you're interested in this nice retro technical instrument. The condition of this instrument is generally very good for a working instrument - it's got very few signs of wear and it has recently been through a check-over and light lubrication. Turning to the main technical details of this vintage monocular polarising microscope, we have a monocular eyepiece giving 6x magnification and you'll see on looking through, that it's got a set of cross-hairs that can be set at two angles corresponding to notches in the top of the optical tube, giving vertical and 45 degree off-set options for the cross-hairs. The coarse focus system moves the main microscope optical tube in a vertical plane, with its controls at the top of the limb. There's a lovely smooth action through the twin-sided thumb-wheels - travel and focus are both good and the tube holds in position as it should.
Fine focus adjustment has been cleaned and lightly re-lubricated so also has a smooth action. There's a useful mixture of three progressive magnification objective lenses on a triple turret as follows.
4x magnification by Vickers Instruments. 10x magnification - J Swift & Son - 40x magnification - J Swift & Son.
The effective overall magnification available therefore ranges from 24x to a respectable 240x with good illumination. The instrument tilts for inclined viewing and holds in position well, it can be tightened further if required.The main optical tube has a number of adaptations specific to polarised light microscopy as follows. A lever operated iris in the top of the tube - a polaroid analyser on an in/out slider - a second in/out slider with reduced aperture - a slot for inserting compensation plates - these are not supplied - centering via two small thumb-screws. The specimen stage is a circular design in brass with a 360 degree scale and removable centre section. The stage which rotates freely with just the right level of resistance to the touch and it can also locked in position via a thumb-screw mechanism. There's two chromed slide clips for holding samples in place during viewing sessions which are fine for holding petrological/geological slides of various sizes. You'll see in the listing photos that for testing purposes I was examining an over-size geological thin-section mineral slide. Below-stage there's a specialist polarising hardware comprising condenser, there's also a working iris, rotatable polarising filter with external degree scale and a 35mm swing-out filter carrier. Extinction can be achieved by setting the analyser to "in" and then rotating the lower polariser until all light is extinguished when the polarisers are crossed. Sample illumination is provided via a standard 2 inch plano-concave mirror on an swiveling gimbal mount, with period silvering that's in very good condition to both sides. The overall condition of this polarising microscope is really good, it's easy to use and it's got the benefit of little evidence of wear with virtually no nicks to the black paint finish that I can see anywhere on the instrument.
In summary, this is a well-equipped functional vintage research-grade polarising microscope from quality British optical firm J Swift & Son that may therefore appeal to collectors of technical equipment and also users requiring transmitted light and polarising capabilities. It's also got an imposing retro look and is just the right size to make it a great technical display piece. There's currently no storage case for this example and I will endeavour to source a suitable case in the near future and add it to the listing if/when I can.