Undergoing Preparation - Further Photos to Follow. Here we have an interesting vintage specialist microscope - it's a Petrological/Petrograhic microscope from renowned manufacturers J Swift & Son of London.
This example probably dates from around the 1950s/1960s. This type of microscope is configured for use in Petrology and Optical Mineralogy using a technique called polarised light microscopy (PLM) so that thin-sections of translucent mineral samples can be closely examined using polarised light in order to determine their mineral content. The microscope can also be used as a normal bright-field microscope to view conventional slides by swinging the polarising filters out of the optical path.
Petrological microscopes usually differ from standard bright-field microscopes in the following ways. A Nicol Prism polariser filters the light beneath the sample slide - a circular specimen stage is used, with 360 degree vernier scales. A second Nicol Prism (called the analyser) is added between objective and eyepiece - a Bertrand Lens is added allowing the viewer to see interference patterns. This microscope can therefore be set up to view thin sections of rocks/minerals using PLM techniques - something for the experienced petrologist perhaps.
In addition, the microscope can also be used to view normal samples using conventional sub-stage illumination without the use of polarisation, so it's essentially dual-purpose. The main technical details of this quality microscope are as follows.Swift Telaugic eyepiece with 10x magnification in a monocular unit. Main focus is by rack and pinion which has a nice smooth action through the twin chromed thumb-wheels.
Fine focus is via vernier adjustment which also appears to have a nice smooth action. Main tube is fitted with a Bertrand Lens, Nicol Prism analyser and an iris to control lighting. There are a total of five objective lenses with progressive magnification and there's a rotating triple turret: J.Swift - 10x Unnamed objective - 20x Prior - 42x Watson - 100x. The circular specimen stage with its silvered 360 degree scale is fitted with two stage clips and is a joy to use. It rotates freely with just the right amount of resistance - it can also be locked in position via a single thumb-screw. The condenser is on a rack and pinion height adjustable mount, with fully working iris and swing out filter holder.
It also has swing-over aplanatic/chromatic correction. The sub-stage polariser is on a swing-out mechanism, to allow the microscope to be used to view conventional samples.Illumination is via a multi-adjustable plano-concave mirror with silvering to both sides that's in good functional condition. The overall condition of this microscope is excellent and there is only minor wear to the black paint finish in areas where one would expect to see some signs of wear for a vintage piece.
The microscope also tilts and locks in position as required. There is also an original quality fitted wooden case with this microscope together with working lock and key.In summary, this is a superb vintage Swift Petrological/Petrographic microscope with quality fittings and a good set of optics. It's ideal for specialist petrological applications using polarised light and also fine for viewing conventional slides and specimens. Owing to its weight the microscope will be dispatched by insured courier upon receipt of cleared funds. Thanks for looking - please also check out my other listings - mainly eclectic artworks and vintage optics, plus some other cool stuff. Swift & Son Petrological /Petrographic Microscope, Cased, Watson Lens" is in sale since Wednesday, January 1, 2020. This item is in the category "Antiques\Science/Medicine\Scientific Instruments". The seller is "arcboutant" and is located in Glasgow. This item can be shipped to United Kingdom, Antigua and barbuda, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Australia, United States, Bahrain, Canada, Brazil, Japan, New Zealand, China, Israel, Hong Kong, Norway, Indonesia, Malaysia, Mexico, Singapore, South Korea, Switzerland, Taiwan, Thailand, Bangladesh, Belize, Bermuda, Bolivia, Barbados, Brunei darussalam, Cayman islands, Dominica, Ecuador, Egypt, Guernsey, Gibraltar, Guadeloupe, Grenada, French guiana, Iceland, Jersey, Jordan, Cambodia, Saint kitts and nevis, Saint lucia, Liechtenstein, Sri lanka, Macao, Monaco, Maldives, Montserrat, Martinique, Nicaragua, Oman, Pakistan, Peru, Paraguay, Reunion, Turks and caicos islands, Aruba, Saudi arabia, South africa, United arab emirates, Ukraine, Chile, Bahamas, Colombia, Costa rica, Guatemala, Honduras, Jamaica, Kuwait, Panama, Philippines, Qatar, Trinidad and tobago, Uruguay, Viet nam.