I just watched “In the Heart of the Sea” about Moby-Dick and Herman Melville. It seems a lot of labour and danger to kill whales to get oil for light and heating. Wikipedia says petroleum was known in ancient Persia and also China. Why wasn’t this more explored and used?
world history of oil mentions use in street lights in Poland in 1500, and it seems by then Europe had some idea about oil. Compared to the use of eg. coal it just seems to have been no interest in petroleum until the wells started in Pennsylvania in 1850s.