I did a piece on the Multiplying Balls for the swedish magazine "Trollkarlen" a couple of years ago. It was around 16 pages, so I can't post it here. But a few of the details:
"The history of the Multiplying Ball effect isnt as ancient as one might believe, but it is all the more messy. The origin has been tracked back to Buatier de Kolta, who in 1875, for the first time ever, performed an effect where one ball magically was produced, and then multiplied into three balls. However, the choreography was quite different from what is considered standard today. In de Koltas original, the balls were held together in one hand, from underneath the hand acting almost as a basket for the balls, while all the magic was performed with the other hand. As noted by Tommy Wonder, the original effect was more elegant than the versions known today. But where has todays standard handling appeared from? The history here gets trickier to follow.
"In Hoffmans book More Magic (1889), Hoffman describes, with credits to de Kolta, a small variation. But the choreography and effect is still basically the same.
"The first time a version similar to the modern handling is published is in the August issue 1900 of a German magazine, Carl Willmanns Zauberwelt. There are no credits in the description, but it isnt claimed as a new piece either. And the piece has the somewhat odd title (in translation) The Chicago Balls.
"So, the origin of the modern standard choreography seems to have appeared between the publication of Hoffmans book in 1889 and the published effect in Zauberwelt 1900. And in the latter, there is an odd reference to Chicago. Going through the records, it turns out that the only connection Willmann had to Chicago, was that he was doing business with a German-born dealer of magic props named August Roterberg.
"During this period, August Roterberg published two books, both containing effects with balls: The Modern Wizard (1894) and Latter Day Tricks (1896). Curiously enough, these pieces make use of the same props as todays standard routines, but the choreography is still an emulation of de Koltas.
"But it still seems like Roterberg is the creator of todays standard version, because soon after the publication of Latter Day Tricks, he published a small manuscript (together with the props) titled: Excelsior Ball Trick, and here all the pieces in the puzzle is in place. Both the props and the choreography is the same as what is known as standard today, and the balls are produced between the fingers."
... Then, thanks to Richard Hatch, I continued with the story of George F. Wright, from John Braun's column in Linking Ring.
Don't know if this is of any use, and my research might be flawed, as I've relied a lot on second hand information.