Vintage--BRASS-- Household door- Or RAIL-- portable Light bulb Holder-- WAS Silver plated--Copper  Dipped -Brass before Silver plating-- Silver is gone-- copper is showing-- Brass under the copper

PAT. APPLIED FOR-- on Round before swivel--see pictures--- so early century

 light bulb head swivels around-- NOT TESTED HEAD--- NO CORD--- Runs thru head and then Tube above holder--see pictures
1-13/16 " wide on door or rail
2-5/8" tall total
7 " long as shown  with light bulb socket

Something different-- something unique---see pictures for best description on condition
 any questions-please ask