Another thing that stood out to me from HITCHCOCK TRUFFAUT; apparently, a great many films from the silent era were based on plays. That is fascinating, because dialogue tends to be the core story engine of playwriting, whereas silent filmmaking is concerned, you have to do without dialogue altogether, save for a handful of title cards.
It's got me thinking about adapting plays to silent comix and all the different changes one would have to make along the way. Changes that would inevitably alter the plays rather drastically I think.