“Amberite (Bulk) Smokeless Sporting Powder” was introduced by Curtis & Harvey in 1893. In 1894, John Hall & Son introduced “Cannonite”, manufactured by the War and Sporting Smokeless Powder Co.

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Hall & Son was acquired by Curtis & Harvey in 1896 and "Cannonite" became “Smokeless Diamond” in 1903.

I don't think "Amberite" was marketed in the U.S., and it is not mentioned here
https://books.google.com/books?id=Wv0MAQAAIAAJ&pg=PA442&lpg

It is included here with "Cannonite"
https://books.google.com/books?id=BFRDAAAAIAAJ&pg=PA66&lpg

I couldn't find a reference to "blended Amberite", but "Amberite No. 1" was a mixture of nitro-cellulose, nitro-glycerin, paraffin, shellac, with ammonium carbonate
https://www.usni.org/magazines/proceedings/1896/july/notes-literature-explosives

Curtis’s & Harvey ad in 1908.
“E.C.” was marketed in Europe "Ruby" or "Poudre Rose E.C".

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