After graduation he worked as an exploration geologist in Canada from 1956 to 1958. near
Buxton, (1959-63) The centre employed a number of Britain's leading climbers as instructors and Langmuir appointed
Joe Brown as the chief instructor. From 1963 to 1969 he was the Principal of Glenmore Lodge Outdoor Centre near
Aviemore. Prior to his appointment, Glenmore was known for hosting residential courses for schoolchildren, but under Langmuir's influence its focus moved towards providing specialised training in mountain skills, particularly for aspiring mountain leaders. He later became a member of the Mountain Rescue Committee of Scotland and was its chairman from 1968. in
Edinburgh, that and a following publication established a framework for a better understanding of avalanche risk in the Scottish mountains. In 1976, he became Assistant Director of the
Lothian Department of Leisure Service, where his responsibilities included the
Hillend ski centre, which had been opened ten years earlier as Britain's largest artificial ski centre, a new sailing training centre at
Port Edgar and the setting-up of the
Pentland Hills Regional Park. ==Work in mountain training and safety==