Antique Vintage Brass G.P.O Tangent Galvanometer NO RESERVE For Sale
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Antique Vintage Brass G.P.O Tangent Galvanometer NO RESERVE:
$265.74
AntiqueVintage Brass G.P.O Tangent Galvanometer NO RESERVE
All of myauctions have NO RESERVE.
ItemDetails: Antique Vintage Brass G.P.O TangentGalvanometer.
Part of a smallsingle owner scientific collection for sale this week. I do not know how tooperate these instruments and in some cases I do not know what their use is,they are all therefore sold as untested collectable scientific objects and soldas seen, with no guarantee that they work.
Please see picturesfor all details, they form part of the description.
This auction is for aSuperb quality Brass Tangent Galvanometer dating from the early 20thcentury. Beautifully made, very heavy and in good condition but with no obviousmakers name. The base of the compass has two mirrors, both of these have acrack, all else looks excellent. Marked G.P.O and probably had a use to do withTelegraphs.
(Information on useas found via google) “The tangentgalvanometer was first described in an 1837 paper by Claude-Servais-MathiasPouillet (1790-1868), who later employed this sensitive form of galvanometer toverify Ohm\'s law. To use the galvanometer, it is first set up on a levelsurface and the coil aligned with the magnetic north-south direction. Thismeans that the compass needle at the middle of the coil is parallel with theplane of the coil when it carries no current. The current to be measured is nowsent through the coil, and produces a magnetic field, perpendicular to theplane of the coil, and directly proportional to the current. The magnitude ofthe magnetic field produced by the coil is B; the magnitude of the horizontalcomponent the earth\'s magnetic field is B\'. The compass needle aligns itselfalong the vector sum of B and B\' after rotating through an angle Ø from itsoriginal orientation. The vector diagram shows that tan Ø = B/B\'. Since themagnetic field of the earth is constant, and B depends directly on the current,the current is thus proportional to the tangent of the angle through which theneedle has turned”.
Pictured with ameasure for size.
I will combineshipping costs if you buy several pieces. You will pay the single mostexpensive shipping cost in full and all other shipping costs will be reduced by50%.
Payment: Preferred payment iscash on collection, a cheque in advance, Bank Transfer or Pay Pal if unable topay the other ways.
Post& Packaging: UKFREE. Europe £35. USA & Canada £38. Rest of World £45.
