Complex sentence: It was through Herbertson that Crawford was introduced to the geographer Patrick Geddes., but Crawford decided to focus his attentions on archaeology rather than geography even though few professional positions in the field existed in Britain at the time.
Split into simpler sentences: It was through Herbertson that Crawford was introduced to the geographer Patrick Geddes. Crawford however decided that he wanted to focus his attentions on archaeology rather than geography; attempts to find a professional position in the field were hindered by the fact that very few existed in Britain at the time.