Wirt "Dim-A-Lite" pull-cord dimming socket adapter

Wirt "Dim-A-Lite" pull-cord dimming socket adapter

<< >>
Usage conditions apply
Description (Brief)
Wirt "Dim-A-Lite" lamp socket, c 1909. Brass shell with brass medium-screw socket and porcelain insulator. Bolted contact, mica insulator inside. Slide mechanism external with two pull chains wrapped around back of shell. Different colored bead finials tied to cords (one missing) that are attached to the chains indicate direction of light adjustment. Shell stamped: "Wirt.E.S.Co.Phila.Dim.A.Lite.Pat.Nov.24.08." The patent is US Patent 904826, "Lamp Reducer," issued to Charles E. Wirt. Hammer Collection.
Currently not on view
Object Name
lamp dimmer
lamp socket
Other Terms
Socket with Dimmer; Components; Power and Lighting; Power and Lighting
date made
ca 1909
overall: 2 1/2 in x 2 1/8 in x 1 3/4 in; 6.35 cm x 5.3975 cm x 4.445 cm
ID Number
catalog number
accession number
Credit Line
from International Business Machines, Inc., William J. Hammer Collection
See more items in
Work and Industry: Electricity
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Hi Alice. This object probably dates from the early to mid 1910s. There's a patent date of 24 November 1908 stamped on the shell. (The photos are a bit too low in resolution to make that out.) That date refers to US Patent #904826, "Lamp Reducer," issued to Charles E. Wirt. We have a few other Dim-A-Lites stamped "patent pending" that were probably made between the patent's 18 March 1907 filing date and the issue date. I expect it would have taken Wirt and his company a few weeks to modify their production machines. So for this particular unit, and the others we have that are also stamped with the date, all we can say for certain is that they were made in or after 1909. I've updated the catalog record on this and the other Wirt units, and that update should push out soon. Thanks! Hal
Hello - do you happen to know the date of this piece please? Thank you,

Add a comment about this object