Armat worked for Edison .
Armat refined the projector in 1897 by replacing the beater mechanism with a more precise Geneva drive , duplicating an invention made a year earlier in Germany by Oskar Messter and Max Griewe and in England by Robert William Paul .
Working for Edison , Armat refined the projector in 1897 by replacing the beater mechanism with a more precise Geneva drive , duplicating an invention made a year earlier in Germany by Oskar Messter and Max Griewe and in England by Robert William Paul .