Complex sentence: After leaving Heatherley's, Bentley worked without pay as a clown in a circus; when this job ended he was a film extra, and during the General Strike of 1926 he worked on the London Underground.
Split into simpler sentences: After leaving Heatherley's, Bentley worked without pay as a clown in a circus. When this job ended, he was a film extra; and during the General Strike of 1926 he worked on the London Underground.