Complex sentence: In 1880 He found work at the Winter Palace allowing to sleep at the premisis, this allowed him to bring in packets of dynamite each day, concealing it in his room, within his bedding.
Split into simpler sentences: In 1880 He found work at the Winter Palace. He was allowed to sleep at the premisis, which allowed him to bring in packets of dynamite each day, concealing it in his room, within his bedding.