After working at the British Museum for more than forty years, in 1909 Jenner and his wife Kitty retired to Hayle, his wife's home town, and in January 1912 he was elected as the Librarian of the Morrab Library, a post he held until 1927.
Despois de traballar no Museo Británico durante máis de corenta anos en 1909 Jenner e a súa dona Kitty establecéronse en Hayle, a cidade natal da súa esposa, e en xaneiro de 1912 converteuse en bibliotecario da Morrab Library, un posto que ocupou ata 1927.