Dr. Bose reached the age limit of 55 on the 29th November 1913 but he
was granted an extension till the 13th September 1915. The period of his
extension having expired, he retired from the Professorship in the
Presidency College after 31 years of service. The Governing Body of the
College, however, "in recognition of his eminent services to Science and
Presidency College," appointed him _honoris causa_ Emeritus Professor of
the College. His duties as a member of the staff ceased. But he was
given facilities to continue his work in the Physical Laboratory of the
College.[45]