Complex sentence: In 1841 the original jail which was commissioned in 1749 was destroyed in a fire which resulted in new jail being formed and was in use until the 1940s when it was converted into an emergency communications (dispatch) office.
Split into simpler sentences: In 1841 the original jail, which was commissioned in 1749, was destroyed in a fire. This resulted in a new jail, which was used until the 1940s when it was converted into an emergency communications (dispatch) office.