Abstract, 'On the expansion of wood by heat' by James Prescott Joule Joule writes that the expansion of wood cut in the direction of the grain is greatly influenced by the tension to which it is exposed, as well as by its humidity. Subject: Physics Received 5 November 1857. Read 26 November 1857. A version of this paper was published in volume 9 of the Proceedings of the Royal Society as 'On the expansion of wood by heat'. 1857