Vintage/Antique Portable Potentiometer, Tinsley & Co. 3184D, Good Condition

Description

This is an antique potentiometer, Model 3184D, built by Tinsley & Co in Essex, UK. The company still exists and still produces precision instrumentation to this day. This device was originally used to measure and characterize test cells, such as emf (voltage) and internal resistance. Inside the unit is an area for two 3V batteries and a Standard Cell to provide a known emf, by which the measurements on the unknown test cells are made. The actual measurements are made with a deflection meter, the components of which appear completely intact.
The unit is in good shape, as shown in the pictures. These types of devices can be used to measure very small potential differences, down to the microvolts even. A functional schematic is shown, and it appears a previous owner added a toggle switch to one of the power lines, possibly to save battery life when not in use. If you're in need of some spare parts, I'm willing to bet this thing is stocked with precision resistors.
Solid wood case, very sturdy construction, weighs about 22 lbs. The outside has some wear and tear as you would expect from a used piece of equipment, but it's overall quite nice. The top cover is easily removed from its hinges so it would make a great decoration on a bookshelf or in a cabinet.
They really don't make 'em like this any more!
Offered for sale is a rare antique brass Sundial by P. Le Maire, Paris, circa 1720 with the original case in outstanding condition. This octagonal dial insert with a compass, adjustable gnomon with bird-form indicator, rear engraved with European cities, latitudes and longitudes in a fitted case. #105
Description: An early 18th-Century silver Butterfield-pattern compass sundial, signed on the horizontal plate Le Maire Fils A Paris, engraved with the hours for latitudes [?]52°, 49°, 45° and [?]42°, the inset compass with sixteen compass points, blued-iron needle with brass cap and glazed cover, the folding gnomon with bird-shaped pointer, and graduated 40° - 60°, the underside engraved with the latitudes for twenty-four cities and towns, supported on a turned foot.
This 18th-Century brass Butterfield-type compass sundial, signed P. Le Maire A Paris, the octagonal base plate engraved with foliate panel and four hour scales marked 52 de 4 - 12 - 8, 49 de IIII - XII - VIII, 46 de 4 - 12 - 8 and 43 de V - XII - VII, the folding, spring-loaded gnomon engraved with foliate motifs and latitude scale 40° - 60° running against a pointer in the form of a bird, the compass with engraved rose and brass-capped, blued-steel needle, the underside engraved with the names and latitudes of 31 European cities, in fitted, blue plush-lined, leather-covered case -- 3in. (7.5cm.) long.
Literature: BAPTISTE, Georges (ed.) La Measure Du Temps (Brussels, 1984);DAUMAS, Maurice Scientific Instruments Of The Seventeenth And Eighteenth Centuries And Their Makers(London, 1972). GUYE, Samuel and Henri MICHEL Time & Space Measuring Instruments From The 15th To The 19th Century (London, 1971);MADDISON, F.R. A Supplement To A Catalogue Of Scientific Instruments In The Collection Of J.A. Billmeir, Esq., C.B.E. (Oxford and London, 1957);SYNDRAM, Dirk s  Und Sonnenuhren (Munich, 1989)
Provenance: Christie's Dec. 1999.
Notice: Be aware that other merchants (some from India), are selling fake imitations. This is a genuine antique!. Remember - Fake news and fake antiques are  fakes!
This antique vintage French universal equinoctial dial would make a wonderful addition to that antique scientific instrument  collection when placed in a prominent position.
Please look at the photos as what you see is what you are buying.
Please note that the photos form a part of the condition description.
Terms: Please email the seller for purchase arrangements, shipping details, questions, more photos, etc.
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