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.
L. E. Knott Apparatus Company
Date: circa 1900
Object number: 1996-1-0592
Zeiss-Aerotopograph
Date: circa 1950
Accessories: instrument is in original wood storage/carrying case. listed accessories: base plate, mirrors (2) and tubular holders (2), anchors (2), prism yoke, monocular adapter, lighting set with bulbs (3, one currently in lamp, its box in box of 2009-1-0002b), 2 monoculars (4 or 6 power) [6x24 (infinite) L or R Zeiss aerotopo logo), "fork"-shaped support (V rather), green filters (2) , dioptre lenses (2), strabismus-correcting lenses (2), photo holder, permanent magnets (8)
Object number: 2009-1-0002a
