tube sensitometer
Date1930-1950
Inventory Number2006-1-0054
ClassificationTube Sensitometer
Subject
Maker
American
User
David W. Latham
born 1940
User
Oak Ridge Station
1931 - 2005
User
George R. Agassiz Station, Harvard
1951 - 1982
Cultural Region
Dimensions8.3 x 13.5 x 9.6 cm (3 1/4 x 5 5/16 x 3 3/4 in.)
Material
DescriptionThe instrument consists of blackened brass tubes held between two brass plates supported by four columns. The top plate is pierced with holes of equal diameter. The bottom plate is pierced with calibrated holes of varying sizes. One edge of the plate has a beveled track.
Some black electrical tape is stretched around the tubes.
Some black electrical tape is stretched around the tubes.
Signedunsigned
FunctionThe sensitometer was used to produce images of different brightnesses on a photographic plate, which could then be compared to the brightness of star images on photographs taken with an astrograph (photographic telescope).
One side of the sensitometer has many holes of the same size. These are illuminated evenly. On the other side of the instrument, the light exits holes of differing diameters. That light is projected on a photographic plate, producing light spots of different calibrated brightnesses.
The instrument was generally built into a camera.
One side of the sensitometer has many holes of the same size. These are illuminated evenly. On the other side of the instrument, the light exits holes of differing diameters. That light is projected on a photographic plate, producing light spots of different calibrated brightnesses.
The instrument was generally built into a camera.
ProvenanceHarvard College Observatory, George R. Agassiz Station / Oak Ridge Station; transfer to CHSI courtesy of Robert Stefanik at Oak Ridge Observatory.
Historical AttributesThis tube sensitometer was used by astronomer David Latham of the Harvard-Smithsonian Center for Astrophysics to calibrate photographic plates at Oak Ridge Observatory. Latham believes that it dates from the 1930s or 1940s.
Hugh Powell
Date: 1841
Accessories: oculars (2); objectives (3): 1/2, 1/8, 1/4 with attachable Lieberkühn; stage slide holder; stage fish plate holder; X-Y mechanical stage; fish plate; prepared slides (2); plain glass slides (2) and cover slips (2); box of cover slips; sponge; cotton bag; folding scalpel; fish plate; mount for stage forceps; fishhook; assorted hardware; case
Object number: 1164
Sylvania
Date: late 19th-early 20th Century
Object number: RS0368
Andrew Pritchard
Date: 1835-1840
Accessories: objectives (4); oculars (6); lieberkühns (4); stage forceps; bull's eye condenser on stand; spring stage; extra mechanical stage; polarizer; cup diaphragms and holders; substage fork mount; live box; glass troughs (2); concave glass; fish tube holder; case; 2 keys. See also slide micrometers (2) (1088b,c)
Object number: 1088a
Ernst Leitz (company)
Date: circa 1919
Accessories: oculars (2): 3, 8x; accessory box; Leitz objectives (5); wrenches (2); ground glass; N.A. 1.45 condensor cap; Abbe condensor; rotary stage; case
Object number: 1345
Hickok Electrical Instrument Company
Date: 1955-1965
Object number: 1998-1-0879
Troughton & Simms
Date: 1868-1870
Object number: 2006-1-0051
George Erle Beggs
Date: early 20th-mid 20th Century
Accessories: 6 deformeter gauges;
22 plugs;
2 cylindrical plastic boxes containing screws and metal strips for fastening the ends of the structure;
metal stylus;
2 metal pins;
2 celluloid wedges;
1 rectangular celluloid piece with a wedge coming out of one end
Object number: 1999-1-0064
Marloye et Cie
Date: circa 1850
Accessories: horsehair cello bow
Object number: 1998-1-0081