Original: In the 19th century , the idea appeared in universities that a definitive history could be written of a major region of the world for a great span of time  in a similar manner to the way that an encyclopediawas written. The time period was subdivided into eras and one volume specified for each.
Revised: In the 19th century , the idea appeared in universities that a definitive history could be written of a major region of the world for a great span of time in a similar manner to the way in which people compiled an encyclopedia. The chosen time period was subdivided into eras and one volume specified for each.
Edit intent: coherence