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OT: Parthian batteries
- Thread starter beoram
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Besides the electroplating process hypothesis, it seem to me that a battery such as this would be usefull in making & maintaining a magnetized compass needle ...'you know the kind (we all made as kids) where a magnetized needle is placed on a leaf floating in a shallow bowl of water.
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Hmmm, I'd hold back from calling that a battery based upon the given evidence.
A battery is a device to convert electrochemical potential into electricity.
Two dissimilar metals in contact with an electrolyte do make a galvanic cell, but unless one actually makes use of the electric potential between the two different metal pieces, is it a battery?
Note that Volta is credited in 1800 with the (re??)discovery of the battery or "voltaic pile" because he observed the electric potential between the two different metals of a galvanic cell.
Very simply, Volta observed a completed circuit. With an unusual detection device. Try and imagine what else could have served as a serendipitous detection device that was available in 1800, let alone 2,000 years ago. Two volts or less.
But, amost 40 years earlier (and probably even earlier somewhere else), the British Admirality had inadvertantly constructed essentially identical galvanic cells: seagoing wooden ships clad in copper that used iron fasteners. The iron corroded at an inexplicably rapid rate, and they were forced to use copper fasteners. Essentially identical situation, save the observation of electrical potential between the two similar metals and nobody calls this the "discovery of the battery".
Twenty five years after Volta's work, Sir Humphrey Davies attempted with notably limited success to employ iron as a sacrificial element to protect copper sheathing on ships. It was noted that carbonate salts tended to accumulate on the copper under most circumstances which let to a surface that fouled more rapidly than "unprotected" copper, which outweighed the hoped-for advantage of slower corrosion of the copper sheathing.
http://www.phaidros.com/DIGITALIS/images2/sqk00088.gif
The illustration in the link shows no access to the copper cylinder once the apparatus is assembled as suggested--without that it could hardly be considered a battery. Perhaps is is a bad illustration. There is no evidence of salts remaining from electrolytes mentioned either.
Even the presence of the an electrolyte in the apparatus doesn't demonstrate use as a battery--The device may have been used to generate various salts or oxides (depending upon the composition of the electrolite) which would accumulate upon the metals, quite possibly in a very pure form otherwise inaccessable at that time.
If a bunch of metal-plated artifacts are confirmed, I say a that could be suggestive--But museum curators appear to be generally quite reluctant in such cases, especially when they might be proven incorrect, or even accused of being taken in by forgeries.
Or it may be a container that was thought to provide special properties or protection to objects or substances stored therein.
I'll with-hold comment on the "Ancient Astronauts (Astro-Naughts?) link
Well, mostly anyway.
A battery is a device to convert electrochemical potential into electricity.
Two dissimilar metals in contact with an electrolyte do make a galvanic cell, but unless one actually makes use of the electric potential between the two different metal pieces, is it a battery?
Note that Volta is credited in 1800 with the (re??)discovery of the battery or "voltaic pile" because he observed the electric potential between the two different metals of a galvanic cell.
Very simply, Volta observed a completed circuit. With an unusual detection device. Try and imagine what else could have served as a serendipitous detection device that was available in 1800, let alone 2,000 years ago. Two volts or less.
But, amost 40 years earlier (and probably even earlier somewhere else), the British Admirality had inadvertantly constructed essentially identical galvanic cells: seagoing wooden ships clad in copper that used iron fasteners. The iron corroded at an inexplicably rapid rate, and they were forced to use copper fasteners. Essentially identical situation, save the observation of electrical potential between the two similar metals and nobody calls this the "discovery of the battery".
Twenty five years after Volta's work, Sir Humphrey Davies attempted with notably limited success to employ iron as a sacrificial element to protect copper sheathing on ships. It was noted that carbonate salts tended to accumulate on the copper under most circumstances which let to a surface that fouled more rapidly than "unprotected" copper, which outweighed the hoped-for advantage of slower corrosion of the copper sheathing.
http://www.phaidros.com/DIGITALIS/images2/sqk00088.gif
The illustration in the link shows no access to the copper cylinder once the apparatus is assembled as suggested--without that it could hardly be considered a battery. Perhaps is is a bad illustration. There is no evidence of salts remaining from electrolytes mentioned either.
Even the presence of the an electrolyte in the apparatus doesn't demonstrate use as a battery--The device may have been used to generate various salts or oxides (depending upon the composition of the electrolite) which would accumulate upon the metals, quite possibly in a very pure form otherwise inaccessable at that time.
If a bunch of metal-plated artifacts are confirmed, I say a that could be suggestive--But museum curators appear to be generally quite reluctant in such cases, especially when they might be proven incorrect, or even accused of being taken in by forgeries.
Or it may be a container that was thought to provide special properties or protection to objects or substances stored therein.
I'll with-hold comment on the "Ancient Astronauts (Astro-Naughts?) link
Well, mostly anyway.
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- Mar 26, 2002
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Maybe, maybe not.
It could be that there was some sort of serendipitous discovery - someone put certain containers or object together. When he or she took them out, something unexpected had happened. Then maybe someone found a way to do a nifty parlor trick with it - maybe giving someone a mild shock (ever lick a 9V battery?) or magnetizing a needle, or playing with static charges.
Given the value of copper and iron for actual useful implements, I'd suspect that not many of these were around, and that any use would've been reserved for the richest individuals. If that's true, it's pretty miraculous that the thing was discovered in the first place, and little supporting evidence is likely to remain. But the electroplated silver theory is testable (asssuming you can tell electroplating from gold leaf gilding, I imagine so, but I don't know enough to say). In this case, it would only take one definitive example of electroplating (non-fake, from the right period) to show that the cell was in use.
Thanks for the electro-background, Firkin!
It could be that there was some sort of serendipitous discovery - someone put certain containers or object together. When he or she took them out, something unexpected had happened. Then maybe someone found a way to do a nifty parlor trick with it - maybe giving someone a mild shock (ever lick a 9V battery?) or magnetizing a needle, or playing with static charges.
Given the value of copper and iron for actual useful implements, I'd suspect that not many of these were around, and that any use would've been reserved for the richest individuals. If that's true, it's pretty miraculous that the thing was discovered in the first place, and little supporting evidence is likely to remain. But the electroplated silver theory is testable (asssuming you can tell electroplating from gold leaf gilding, I imagine so, but I don't know enough to say). In this case, it would only take one definitive example of electroplating (non-fake, from the right period) to show that the cell was in use.
Thanks for the electro-background, Firkin!