It is one of the first microscopes having as objective a system of lenses able to correct satisfactorily the chromatic aberration. The tube is vertical and is supported by a ring connected by means of a short arm to a vertical bar. The stage consists of a circular plate with a hole in the center. A rotating horizontal disk having four holes of differents diameter allows to restrict adequately the observation field by transmitted light. The observation are possible also by incidence using light coming from a convergent lens placed at the end of a thin adjustable arm fixed to the stage. The eypiece is held by a short tube which can be pulled out of the body of the microscope. The whole optical device can be extracted from its supporting ring. The instrument is equipped with two exchangeable eyepieces while the objective is single. The vertical bar is screwed in a wooden case where the instrument may be kept. Well-preserved. Entirely of brass. Overall height 35 cm. Signed: "Microscope achromatique perfectionne` par Vincent Chevalier Ing. Opt. Brev. Quoi de I'Horloge 69 Paris. Sold by E.M. Clarke 128 Strand London". Mid-19th century.
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