Old plumb bob

I paid $8 for this today at a local junk sale, even my wife thought I did good. The picture sucks, my hands are too shaky I think, maybe too close up. I was wondering why the bottom portion is cast iron and the top either brass or bronze? How would I tell the difference between brass and bronze? It looks like brass to me. Approximately when would this have been made? It has a rather deep threaded piece for the string, does not thread very tight. He said this was his dad's and later said his dad was a junk collector. Half the fun of finding something like this is talking to the guys behind it about their stuff.

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You did good. I accumulate plumb bobs and have hundreds of them, with virtually no duplicates. I have not seen one like yours and would easily pay 3 or 4 times what you paid. I have no explanation for the metal combo.

Nice plumb bob! From what I know the steel points were used because the are more durable and replaceable. If the bob is dropped a brass point could get bent, then the bob is inaccurate.
Jim

Yes to what Jim said. Did some surveying years ago.

Another yes to Jim and Stan. I have seen ones that had been dropped and had a bent tip. Also, as they were used they would swing back and forth against the ground, and the brass would wear down much more quickly than would the brass.

Stew

I did some surveying also Stan. Almost made a career out of it but started boatbuilding and there was no going back.
Jim