Complex sentence: John Frow continued as keeper until the Cape Florida Light was taken out of service in 1878, and he and his father became the first keepers at the new lighthouse at Fowey Rocks.
Split into simpler sentences: John Frow continued as keeper until the Cape Florida Light was taken out of service in 1878. Keeper John Frow and his father Simeon became the first keepers at the new lighthouse at Fowey Rocks.