A Tornado at Sea

George Cupples (2 August 1822 - 17 October 1891) was a Scottish journalist and a writer, who became famous at the end of 19th century for his maritime novels. In particular, his novel The Green Hand: adventures of a naval lieutenant was considered "one of the best sea stories ever written" at the time. His wife, Anne Jane Cupples, also became a famous writer of juvenile and children books.
A TORNADO AT SEA: "What was my horror when I saw the quicksilver had sunk so far below the mark, probably fixed there that morning, as to be almost shrunk in the ball! Whatever the merchant service might know about the instrument in those days, the African coast was the place to teach its right use to us in the old Iris.