Fresnel mirror
Date1850-1900
Inventory Number1997-1-1575
ClassificationMirror
Subject
Maker
French
?
Maker
German
?
Cultural Region
Dimensions34 × 14 × 9 cm (13 3/8 × 5 1/2 × 3 9/16 in.)
Material
DescriptionTwo hinged black mirrors mounted on a square frame acting as a diaphragm. The mirrors can be slightly angled using the thumb screws on the other side of the diaphragm. The mirrors are set in a brass stand with a circular base. This stand, however, may not be original to the mirrors and diaphragm.
Signedunsigned
FunctionA Fresnel mirror is an instrument designed to demonstrate light interference. It is similar to a Fresnel mirror. It consists of two mirrors, one of which adjustable. When a monochromatic light is shone on the instrument, two reflections are generated: a direct one from the fixed mirror and a second one from the slightly angled mirror. The latter creates the effect of a virtual second light source. When these two reflected light beams interact together, as seen on a screen, they produce interference fringes.
For similar mirrors, go to the following website.
For similar mirrors, go to the following website.
Charles-Louis Chevalier
Date: 1835-1840
Accessories: 4 objectives; 4 oculars; inverting ocular; camera lucida; compressorium; galvanic stage; 1/100 mm stage micrometer; liquid trough; 2 bull's eyes; condenser with diaphragm wheel; mechanical stage; trough; eye shield; case with drawer and lid; spare wooden display base.
Object number: 1115
L. E. Knott Apparatus Company
Date: circa 1900
Object number: 1996-1-0592
Charles-Louis Chevalier
Date: circa 1840
Accessories: 2 convertible objectives: 1, 2, 3 and 0,00,000; 2 oculars; simple magnifiers: 3 and 5, with support bracket; extension pillar; bull's eye stage condenser on jointed arm; forceps; 3 prepared slides; box of cover glasses; 1/100 mm stage micrometer; camera lucida; tall bell jar; padlock on chain; case with key; table of magnifications
Object number: 1079
Breton Frères
Date: circa 1850
Accessories: 6 convertible objectives; 4 nosepieces, one with polarizer; 4 oculars; black / white disk; spare round stage with offset diaphragm; camera lucida; light polarizing insert; compressorium by Chevalier; fish trough; 2 prepared slides; 3 cuvettes; brass box specimen holder with compressed slides and collar to attach to microscope; flat case.
Object number: 1274
