His undergraduate degree was in Experimental Psychology at the University of Cambridge followed by a PhD entitled Vocal reproduction of the duration, intensity and fundamental frequency of synthetic speech sounds from University College London in 1962.
Akiko Uxusink-Nagata helped him edit the magazine La Monda Lingvo-Problemo until 1970; in 1974 the task was definitively taken over by a new editor, Simo Milojeviĉ.
In this period, Sadler also cared after the organization of several World Congresses of Esperanto.
Sadler wrote literary works in Esperanto as well; in 1968 he received the award Arĝenta Sprono thanks to his collection of poems Memkritiko ("selfcriticism"), although the preface to the work says that it was originally a manuscript that he found in the library.
In 1986 he was elected a member of the steering council of UEA, responsible for finances; nevertheless he had to resign in March 1987 because of health reasons.