Complex sentence: Thomas Lipton began travelling the world for new items to stock in this store, one such item was tea, since sales had doubled from £40 million from the late 1870s to £80 million by the mid- 1880s.
Split into simpler sentences: Thomas Lipton began travelling the world for new items to stock in this store. One such item was tea, since sales had doubled from £40 million from the late 1870s to £80 million by the mid- 1880s.