hand-held Becquerel phosphoroscope
Date: 1860-1880
Inventory Number: 1997-1-1527
Classification: Phosphoroscope
Subject:
Maker: Louis Jules Duboscq (French, 1817 - 1886)
Cultural Region:
Place of Origin:
Dimensions:
13 x 17 x 15 cm (5 1/8 x 6 11/16 x 5 7/8 in.)
box: 15.2 × 21 × 19.1 cm (6 × 8 1/4 × 7 1/2 in.)
Description:
The phosphoroscope consists of a round metal chamber with a pair of rotating disks inside, arranged so that no light can pass directly through the chamber. The disks have cut-out windows spaced equally at regular angular distances and are turned by the hand crank linked to a gear mechanism. The sample is placed in a specially designed holder into the small opening near the gearing, and it is exposed to the light source through the large rear condensing lens (missing, but similar to 2007-1-0070). The sample is then viewed through the front aperture. By varying the speed of shutter rotation, the duration of the afterglow can be determined. There is still a phosphorescent sample in the glass holder.
In Collection(s)
Signedon chamber, script: J. Duboscq à Paris
Inscribedon chamber, script: Phosphoroscope de E. Becquerel
FunctionThe phosphoroscope was invented by Alexander Edmond Becquerel (1820-1891) in 1859 and was used to measure the amount of time that a phosphorescent substance would glow after being irradiated by a brilliant source of light.
For more information on this type of apparatus, see the description of Adolphe Ganot on Google Books at the following website.
For more information on this type of apparatus, see the description of Adolphe Ganot on Google Books at the following website.