A spectacular piece, which I must illustrate. While Googling, I saw reference to an 1851 $50 LE Humbert Fifty Dollar piece, which is apparently a pattern, and also gold and octagonal. Do you have any info about why it was minted, and do you think it was the inspiration for the 1915 piece?
Thanks for the image. It is
a great coin--and there is also the round companion piece of the same date and mint.
The 1915s coin inspired by the 1851 piece? My immediate reaction was "of course not," but then that's the beauty of having coins you've seen more or less your whole life reintroduced to you by someone with fresh eyes....I don't honestly know about the relation (if any) of the two pieces' shape--but the more I think about what the 1915s coin is celebrating, the more likely it seems that a link between the two could be possible. I'll look some.
What I can say is that the 1851 piece is an "ingot," and as such is outside the Federal coin series (although there was at one time, seemingly, a concerted effort within the coin hobby to include it). The 1851 piece was coined at the assay office in California, by the U.S. Assayer of Gold, who coined gold for the private concern of Moffat & Company. A successor company issued similar octagonal ingots dated 1852.
Again, thanks for the image, and thanks for the new perspective.