Alluard dew point gauge
Date1900-1930
Inventory Number1998-1-0841
ClassificationDewpoint Measuring Instrument
Subject
Maker
Central Scientific Company
1889 - 2000
Cultural Region
Place of Origin
Place of Use
Dimensions20.6 × 12 × 12 cm (8 1/8 × 4 3/4 × 4 3/4 in.)
Material
DescriptionA small rectangular, nickel plated brass box placed vertically on an insulator over a round metal base. The box has two small, round windows, one in the front and one in the back such that one can see through it. The brass box also has a thin brass sheet attached in the shape of a bracket such that its sides protrude from the sides of the box like fins.
The top of the box has a cap with two pipe connectors, one of them currently attached to an old, short rubber hose, and there is an opening directly on top of the cap.
The round base that holds the box also holds a simple vertical stand with a metal clamp that could hold a cylindrical object (a thermometer).
"H5" has been painted in white above the name plaque.
The top of the box has a cap with two pipe connectors, one of them currently attached to an old, short rubber hose, and there is an opening directly on top of the cap.
The round base that holds the box also holds a simple vertical stand with a metal clamp that could hold a cylindrical object (a thermometer).
"H5" has been painted in white above the name plaque.
Signedon plaque: CENTRAL SCIENTIFIC CO. / LABORATORY SUPPLIES / APPARATUS CHEMICALS
Curatorial RemarksDW82 marked on corner of tag, but DW82 is an electrical generator. The object description does not match DW92 or DW72 tag.
FunctionThis is a device for determining the dew point of the air, the temperature at which water begins to condense out of it as droplets.
The brass box would be filled with a volatile liquid, generally ether. Air would then be blown through the pipes, making the ether evaporate and thus lowering its temperature. At the moment that water droplets appeared on the smooth surfaces of the box, the temperature would be taken with a thermometer inserted from the top. The metal fins remained at ambient temperature and were used as contrast the cold metal surface opaqued by the droplets.
The window was used to determine the ether level in the box, and also to help read the thermometer without removing it.
The stand with the clamp would be used to hold an additional thermometer to measure the air temperature.
For more information and pictures for this device, see the documentation at the Robert E. Paselk Scientific Instrument Museum, Humboldt State University. Online at this website.
The brass box would be filled with a volatile liquid, generally ether. Air would then be blown through the pipes, making the ether evaporate and thus lowering its temperature. At the moment that water droplets appeared on the smooth surfaces of the box, the temperature would be taken with a thermometer inserted from the top. The metal fins remained at ambient temperature and were used as contrast the cold metal surface opaqued by the droplets.
The window was used to determine the ether level in the box, and also to help read the thermometer without removing it.
The stand with the clamp would be used to hold an additional thermometer to measure the air temperature.
For more information and pictures for this device, see the documentation at the Robert E. Paselk Scientific Instrument Museum, Humboldt State University. Online at this website.
ProvenanceFrom Allston-Burr Hall, Harvard University.
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
American
Date: 1850-1890
Accessories: paper photocopy of description and usage
Object number: 1998-1-1414
Taylor Instrument Companies
Date: circa 1925
Accessories: stored within the case: paper recording chart, a length of flexible hose, a bulb and glass container with red recording ink
Object number: 2010-1-0020
Carl Zeiss Jena
Date: circa 1926
Accessories: wooden box with two hook-and-eye latches to fasten front opening; in instrument file: instruction book (photocopy); Geissler tube labeled "H2"; carboard tube containing German thermometer C in stainless steel holder that screws into instrument; glass bottle with cork stopper labeled "Monobromnaphthalin, Germany nD=1 658"; small round cardboard box labeled "For Pulfrich Refractometer" containing one tubulure
Object number: 1996-1-0229
French
Date: 1850-1890
Accessories: set includes: thermometers (2); brass stand base; silver vessels on a T tube (2); curved glass tube with cork; stand tube with side neck; stand tube with holder for curved glass tube; brass clamp for thermometers
Object number: 3824
French
Date: 1850-1890
Accessories: set includes: brass stand base; T-shaped tube; hollow tube with side neck; tube with ring stands; brass holder for two thermometers; one thermometer; glass tubes with brass bottoms (2); felt lined, fitted case
Object number: 3825
E. S. Ritchie & Sons
Date: 1868-1895
Accessories: a) two wheels made of an insulating material (ebonite?), solid except for an oval perforation near the edge, and a depression running on one face along its diameter; b) a spark-gap consisting of two brass balls that hold small rods that face each other, their distance adjustable by screws on the balls. The brass balls are mounted on parallel rods (adjustable height) attached to a thick brass rod that can be held from a thinner rod attached to its central section; c) two large screws and a wooden piece in the shape of a quarter-section of a cylinder, which are currently held inside a plastic bag
Object number: 2007-1-0171
Harmanus van Deyl
Date: 1807
Accessories: 2 objectives; 2 eye lenses for a fixed field lens; 1 Lieberkühn; frogplate; bull's eye; stage forceps; spring stage; live box; hand lens; 2 tweezers; 2 boxes with 59 specimen slides; glass disk; black disk; "fish" tube with wire; ivory box of mica cover slips; 5 glass slides; 3 lenses; 2 keys.
Object number: 2002-1-0075a