Accession No
0908
Brief Description
achromatic compound microscope, horizontal, by Charles Chevalier, French, 1840 - 1850
Origin
France; Paris; Palais Royal 163
Maker
Chevalier, Charles
Class
microscopes
Earliest Date
1840
Latest Date
1850
Inscription Date
Material
metal (brass, lead, steel); glass; wood; cloth (velvet)
Dimensions
height 260mm; breadth 120mm; length 200mm box length 308mm; breadth 217mm; height 81mm; 2 slides bag length 93 mm; breadth 70 mm
Special Collection
Robert Whipple collection
Provenance
Inscription
‘Microscope Achromatique Universel,
Invente par
Charles Chevalier
Ingenieur, Opticien,
Palais Royal, 163
a Paris.’
‘Charles Chevalier
Palais Royal’ (on micrometer slide)
Description Notes
Brass; circular lead weighted base; turned brass column; compass joint; horizontal bar to vertical limb which twists sideways and can be clamped by knurled screw at the end of the bar; limb is racked; shoe carries slot-in stage and knurled focussing screw; square stage with fittings for forceps etc.; rotating diaphragm on pivoting arm; fine focus screw below stage; swinging plano concave mirror on shoe round limb; limb fits into socket on column when in vertical position and is fixed by a rod with knurled head; socket with steel rod slots into horizontal bar where it is fixed by a rod with a knurled screw; body push-fits onto the socket; reflecting prism with locating screws fits into angle; draw tube with push-fit eyepiece; body twists around socket; fitted wooden box with 2 pull out trays lined with green velvet; 1 objective which fits with 3 lenses in cells; 1 which does not fit; spare stage; 4 stage clips; articulated arm with condenser lens; lever compressor signed ‘Charles Chevalier’; camera lucida eyepiece, also signed; Lieberkuhn objective [not original] simple lens holder which fits into horizontal arm; forceps; 2 simple eyepieces, 2 dissecting pins. (Box in many respects, appears right - but instrument will not fit in - and there is certainly no place for the base). Old hole for plate for screwing pillar into lid of box. 2 brass micrometer slides, one marked ‘Millimetre in 1000 Parties’, the other ‘1 millimetre divise en 100 parties...’. Longhand table of objectives in the lid.
References
Events
Description
When light travels through an ordinary lens each colour is bent through a different angle. In a microscope this causes what is known as chromatic aberration, whereby a spectrum of colours will appear around the image being viewed. Chromatic aberration was a big draw back when using early versions of the compound microscope.
Chromatic aberration was overcome due to the important work by Lister in 1830 who developed the achromatic lens for microscopes. The new type of lens prevented colour separation by combining two lenses made of different types of glass. The first lens that light passed through would split the colours and the second lens acted to bring the colours back together again. This produced a much sharper and clearer image than was previously achieved.
In the Victorian period the achromatic microscope became a vital tool in medical and scientific research. Improvements to the optical performance of the microscope saw developments in the design and construction of the microscope. The microscope became sturdier and could focus to a finer level.
Scientific instrument makers in the Victorian period who improved the rigidity of the optical tube and the focusing ability of the achromatic microscope include Andrew Ross, James Smith and Hugh Powell.
FM:42169
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