Complex sentence: The last straw was the Bute Dock Act of 1874, which gave the green light for an additional dock at Cardiff, and in August of that year, Jenner petitioned to have the Barry Railway Company wound up, which was finalized in November.
Split into simpler sentences: The last straw was the Bute Dock Act of 1874, which gave the green light for an additional dock at Cardiff. In August 1874 Jenner petitioned to have the Barry Railway Company wound up, which was finalized in November.