Complex sentence: Brakesmen were placed between the waggons, and led by a man on horseback with a flag, the train set off, picking up speed on the gentle downward slope and reaching, leaving behind gentlemen on hunters who had tried to keep up with the procession.
Split into simpler sentences: Brakesmen were placed between the waggons and the train set off, led by a man on horseback with a flag. The train picked up speed on the gentle downward slope and reached, leaving behind gentlemen on hunters who had tried to keep up with the procession.