Final answer:
Earl Hurd's significant contribution to the field of animation in the 1910s was the creation of the Bobby Bumps cartoon series for Universal in 1915, which is regarded as one of the most mature works of the silent era.
Step-by-step explanation:
Earl Hurd is well-known for inventing cels for animation, but in the 1910s, he made a significant contribution to animation with his cartoon series Bobby Bumps. These cartoons, first produced for Universal in 1915, are considered among the most mature and well-conceived works of the silent era.