History of the Peloponnesian War
Thucydides
Thucydides. History of the Peloponnesian War. Crawley, Richard, translator. London and Toronto: J. M. Dent and Sons Ltd.; New York: E. P. Dutton and Co., 1914.
They sawed in two and scooped out a great beam from end to end, and fitting it nicely together again like a pipe, hung by chains a cauldron at one extremity, with which communicated an iron tube projecting from the beam, which was itself in great part plated with iron.