The success of the series led to an explosion of animation, all adaptations of newspaper comic strips, and few of them remembered today. Meanwhile, Cohl saw both "The Story of a Mosquito" and "Gertie the Dinosaur" live at the Hammerstein Theater in New York, and he recorded his admiration of each in his diary. For animation to be practical, it had to move beyond the techniques of Cohl (cut-outs) and McCay (tracing), both of which were arduous, single-person processes. Two men were to independently work out ways around this problem: Raoul Barré and John Randolph Bray. Barré studied art in Paris in the 1890s and was known for his pro-Dreyfus cartoons. In 1920, Cohl told the story of two unnamed visitors that Éclair had forced on him to study his techniques, techniques that they later stole to make their own series. It is possible that these two were Barré and his business partner William C. Nolan. It is possible that Cohl's obvious hostility to his visitors was the result of the knowledge that they were on opposite sides in the Dreyfus Affair. On the other hand, Barré's method for making cartoons quickly, the "slash system", is the exact opposite of Cohl's cut-out system. It is true that Barré's series, "The Animated Grouch Chasers", frequently stole characters and scenarios from Cohl, but then again everyone was doing that. John Randolph Bray, in collaboration with Earl Hurd, developed the patents that nearly made them the Motion Picture Patents Company of animated film. Animation historian Michael Barrier speculates that one of Cohl's unnamed visitors may have been Bray instead of Barré.