Newton was elected Lucasian professor on 29 October 1670. It was his duty as professor to lecture at least once a week in term time on some portion of geometry, arithmetic, astronomy, geography, optics, statics, or some other mathematical subject, and also for two hours in the week to allow an audience to any student who might come to consult with the professor on any difficulties he had encountered. The subject which Newton chose for his lectures was optics. These lectures did little to expand his reputation, as they were remarkably sparsely attended; frequently leaving Newton to lecture at the walls of the classroom. An account of their content was presented to the Royal Society in the spring of 1672.