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GRIFFIN & GEORGE BOXED INSTRUMENT (POST OFFICE BOX)RARE
| Seller: dparker224 ( 4772  )
End Time: 2008-07-13 21:00:16 GMT
Bids: 1
Current Price: GBP 0.99
Location: BARNSLEY, South Yorkshire
Time Left: 0 Seconds |  | | For More Details: Click here | any info most welcome on this interesting looking boxed instrument,ive no idea what it is so i just hope my pictures can describe it for me.it has makers name griffin and george limited.comes in a nice old wooden box with nicely made joints on all corners,some slight wear and scratches on box.it measures about 29cm long,16cm wide,17cm high.inside the plug things can be pulled out,at front it has things you can push down like morse code things.no idea what it does.viewing welcome,also pickup welcome to save on postage.good luck and happy bidding in this auction,ill happily combine postage if you buy more than one item,please view my other items most bought many years ago when i was younger,but now need the space as kids growing up so most starting at 99p with no reserve,all sold in untouched condition and as seen,any questions welcome.
IVE JUST BEEN GIVEN THE FOLLOWING INFORMATION BY A VERY KIND EBAYER...Hi, The apparatus is known as a "Post Office Box". It is a form of "Wheatstone Bridge", and is used to measure electrical resistance. The box contains a range of accurate resistance coils, with their values narked in ohms on the black surface above them. These are arranged as 3 resistance boxes. Two have values from 10 to 1000, and the third has values 1 to 4000 ohms. It also has two switches, and some terminals to which connections can be made. The box is connected to an unknown resistance, a galvanometer, and a cell (or battery). It is then possible to "balance" the circuit and make a calculation which will give a value for the unknown resistance...
On 08-Jul-08 at 17:26:00 BST, seller added the following information:ive just been given some more info by another very kind ebayer...Just to give you a bit more info- the PO box you have is made by Griffin & George, a firm formed in 1957 of the merger of W&J George & Becker Ltd and Griffin & Tatlock Ltd., they manufactured pretty much exclusively for education. this box features in a catalogue for 1969 although it was produced from the late 50s. production was discontinued in the 1970s when griffin was taken over by A.Gallenkamp and then Fisons although a similar unit using the same "belling & Lee" plug keys remained in the catalogues until about 1997. The flaw in the design is that students like to pinch the keys rendering the boxes useless! Griffin is now a trade name of the american company Fisher Scientific. | |
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