Humphrey’s academic career involved not only extensive research on sub-Saharan Africa (see his Academic Career and Nachtigal), but also many trips to Africa, ranging from a few weeks to whole years. Each trip provided an opportunity to collect and create unique historical primary sources for future research:
- photographs of Arabic manuscripts in Sierra Leone’s national archives, manuscripts which may or may not have survived the civil war
- recorded interviews of Muslims from many different groups in recently independent Nigeria and Sierra Leone about their religious history and experience
- recordings of Christian services of different denominations in the same countries
- Humphrey’s own extensive journals of his African trips and research, providing unique insights into Nigeria, Sierra Leone, Ghana, Liberia, Gambia and Sudan either in early independence days or up to the 1980s. Some of these journals are archived, each with an extensive index, in the library at the School of Oriental and African Studies, London University. Others are still being prepared to be archived.
- Humphrey also took numerous slides documenting places, mosques and churches, flora and fauna and life with a young family during their time together in Nigeria around 1959 and in Sierra Leone in the mid-60s. The slides were meticulously labelled by Helga.
All the sound recordings and the slides have now been digitised at the Uist Digitisation Centre in the Outer Hebrides, Scotland.