They had ZERO magnetic signal, and finding those was another story.
I have never found aluminum monuments before, and we were at a loss as to how one would have gotten ahold of aluminum pipes - what they would have been used for, how expensive they would have been, etc. Anyone know about aluminum in general? I would have thought in 1958, aluminum was more of a costly metal. Any ideas or input would be appreciated.
-Bryan
Aluminum pipes found from 1958
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btaylor
- Posts: 501
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- Location: Foster City, CA
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Ian Wilson
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- Joined: Sat Aug 03, 2002 6:58 am
- Location: Bay Area
Steady on, mate! 1958 is only 50 years ago!
While it is true that the production of aluminum was once so energy intensive that it cost roughly the same price as .999 fine silver, it is no longer considered a "precious metal". In the 1880's an American, Charles Hall, and a Frnechman, Paul Heroult, arrived at the modern production process. The Hall process lowered the production costs so much that it sold for pennies a pound!
Note that the Hall process was developed in the 1880's, 70 years before these pipes were set. As Sean says, surveyors were/are a "frugal" lot. There would have been many sources for scrap aluminum pipe in the 1950's.
While it is true that the production of aluminum was once so energy intensive that it cost roughly the same price as .999 fine silver, it is no longer considered a "precious metal". In the 1880's an American, Charles Hall, and a Frnechman, Paul Heroult, arrived at the modern production process. The Hall process lowered the production costs so much that it sold for pennies a pound!
Note that the Hall process was developed in the 1880's, 70 years before these pipes were set. As Sean says, surveyors were/are a "frugal" lot. There would have been many sources for scrap aluminum pipe in the 1950's.
Ian Wilson, P.L.S. (CA / NV / CO)
Alameda County Surveyor
Alameda County Surveyor