Complex sentence: During the 1870s Jesuit astronomer father Angelo Secchi S.J. was often a guest at the villa, he was a close friend to the Marquess, and used the terrace for his observations of the heavens.
Split into simpler sentences: During the 1870s Jesuit astronomer Father Angelo Secchi S.J. was often a guest at the villa. He was a close friend to the Marquess, and used the terrace for his observations of the heavens.