VINTAGE L.E. KNOTTS APPARATUS COMPANY SLIDE WIRE WHEATSTONE BRIDGE RESISTOR BOX

Description

VINTAGE L.E. KNOTTS APPARATUS COMPANY SLIDE WIRE WHEATSTONE BRIDGE RESISTOR BOX.
A WHEATSTONE BRIDGE IS AN ELECTRICAL CIRCUIT USED TO MEASURE AN UNKNOWN ELECTRICAL RESISTANCE BY BALANCING TWO LEGS OF A BRIDGE CIRCUIT.
MADE IN BOSTON, MASSACHUSETTS OF COPPER, BRASS AND WOOD. MEASURES 24 ½" LONG AND 6 ¾" WIDE.  THE 50MM LONG SCALE IS GRADUATED IN MILLIMETERS AND IS MOUNTED TO A HARDWOOD BASE.  THE WOOD BASE HAS A VERY SLIGHT WARP.  TYPICAL SIGNS OF AGE WITH SOME LIGHT CORROSION ON THE COPPER.  THE SLIDE IS NO LONGER MOVABLE.
GREAT OLD ELECTRICAL APPARATUS.
***payment required within 3 days of auction close.
***we are always happy to combine postage for multiple purchases.
***items are mailed thru the U.S.P.S. and delivery confirmation is included with each item sold.