Grim Natwick and his "kid assistant" Chuck Jones at Ubbe Iwerks in 1933, graphite on 12 field animation paper by Grim Natwick.  

Stephen Worth, the art historian for ASIFA-Hollywood has written a detailed account of the impact that the artist and animator, Grim Natwick, had on the nascent animation film community.  Natwick's story is the story of animation in America and I think you'll find it a marvelously entertaining and informative read (plus there's a terrific short interview with Natwick about Ub Iwerks, where he met and worked with a young animator named Chuck Jones.)  

All of the posts on Natwick can be found here.

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