Microscope phakomètre; brass; part silvered; stand: moulded brass base; central steel column flanked by four thin steel scrolls; instrument is fixed to column by an assembly consisting of a central ball moving within split socket and two clamps; silver champlevé dial with outer ring: graduations 0-360 degrees anti-clockwise; inner ring: chapters I-VI; within ring: two plaques; two steel hands geared together; fixed slide-carrier mounted above dial; simple microscope mounted on two threaded rods each carrying brass pinion of eight leaves; second part of instrument: silvered dial; with domed cover-glass, with outer ring of graduations; two more plaques within an inner ring; steel hands; fixed vertical mica-covered brass plate with two vertical sliders.
- Made in: France
- Height: 385 millimetres
- Depth: 170 millimetres
- Width: 129 millimetres
A real "Phakometer" (an instrument for testing the accuracy of lenses) was invented by Snellen in 1876. Instruments of this kind are to be found in Utrecht (University Museum) and Leiden (Boerhaave Museum). [see objectfile; Sa 15 Oct 1996, 28 Oct 1996].Jones 1990
This complicated 'instrument' does not perform any useful purpose and was presumably made as a spoof. The use of the word 'phlatergometre' may have an intentional connection with the Dutch or Flemish word Flater meaning 'blunder', while phakometre (fakometer) speaks for itself.Ward 1981
The stand of the instrument consists of a moulded brass base, diameter 140 mm, height 27 mm, from which rises a central steel column flanked by four thin steel scrolls. The instrument is fixed above the top of the column by an assembly consisting of a central ball moving within a split socket and two clamps, so that it can be set over a range of angles to the horizontal. It consists of two separate parts, one mounted immediately above the pivots and the second bracketed to this one, with sliding adjustment in both horizontal directions.
The first part has a silvered champleve dial, diameter 63 mm, with an outer ring of graduations 0·-360· anticlockwise, numbered every ten, and an inner ring of chapters I-VI, also anticlockwise, with symbols at the half-units and an inner ring of quarter units. Within this ring are two plaques engraved MICROSCOPE and PHAKOMETRE. Two steel hands, the shorter of them pierced, are
geared together so that four revolutions of the longer correspond to one unit of the inner ring of figures: i.e. a 24:1 gearing. A fixed slide-carrier is mounted above the dial, and in front of this is a simple microscope mounted on two threaded rods each carrying a brass pinion of eight leaves (16 threads = 9 mm). One revolution of the longer hand on the dial corresponds to a miscroscope lens
movement of 9/16 mm.
The second part of the instrument has a silvered champleve dial, diameter 34 mm, with a domed cover-glass, with an outer ring of graduations 0-360 anticlockwise numbered every ten and an inner ring I-IX with marks at the half-units and an inner ring of quarter units. Within this ring are two plaques engraved EPANAPHORASCOPE and PHLATERGOMETRE. The steel hands, the shorter of which is pierced, are geared together so
that four revolutions of the longer correspond to one unit of the inner ring of figures, i.e. a 36: 1 gearing. Behind the dial is mounted a fixed, vertical mica-covered brass plate, 53 X 34 mm, with two vertical sliders, one adjustable by hand through a lead screw, and one from a pair of nuts on a pair of threaded rods with nine threads to 6 mm. One turn of the thread corresponds to one revolution of the longer hand on the dial, which is thus equivalent to a traverse of 2/3 mm. The mica-covered plate is surrounded at the top and sides by a band of pierced steel scrollwork.
1992 Mar-1993 Jan, Canada, Québec, Musée de la Civilisation, True or False or: Beyond Reality
-3-1996/FEB Stand loose.
Britain, Europe and Prehistory
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Object reference number: MCC4013
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