Here we see a small Chinese cast-iron cannon, 39 inches in length, with a bore of 1.1 inches, which had been mounted on a pivot, and is dated to the sixteenth or seventeenth century. It was captured by a British expeditionary force to Benin in Africa in 1897, having somehow made its way there from China. The barrel-strengthening hoops are intrinsic to the casting. (From Fig. 177, Temple 1986: 245).
The above image was taken from The Genius of China, a grotesque little picture book by Robert Temple (yes, he of The Sirius Mystery) seemingly intended as much to as to sneer at European lassitude and deficiencies of imagination as to exalt the Chinese capacity for creation. As far as popular works go, The Genius occupies place of honor in that Anglophone tradition of pseudoacademic Sinophilia for which Gavin Menzies is only the most recent and most embarrassing torch-bearer, but, in spite of itself, it manages to relate a number of thought-provoking trends and picturesque episodes.
As for the specific item at hand, Joseph Needham (1986: 331), author of Temple’s introduction, offers a few more details:
Needham, J. (1986). Science and civilisation in China (Vol. 5, Part 7). Cambridge: Cambridge University Press.
Temple, R. (1986). The Genius of China: 3000 Years of Science, Discovery, and Invention. New York: Simon and Schuster.