Conversation so far:
Did Robert Hughe the critic go to school?
Robert Hughes was educated at Saint Ignatius' College, Riverview before studying arts and then architecture at the University of Sydney
What was Robert Hughe the critic's first job?
Robert Hughes, an aspiring artist and poet, abandoned his university endeavours to become first a cartoonist and then an art critic for the Sydney periodical The Observer, edited by Donald Horne.

Question: How long did he keep his first job?
Self-contained rewrite: How long did Robert Hughes keep his first job as art critic for the Sydney periodical The Observer,?