Complex sentence: The following year a railway west from Paddington to Hammersmith was built jointly by the Great Western and Metropolitan Railways, and the line was extended to the east in stages, reaching the East London Railway in 1884.
Split into simpler sentences: The following year a railway west from Paddington to Hammersmith was built jointly by the Great Western and the Metropolitan Railway. The line was extended to the east in stages, reaching the East London Railway in 1884.