Unpublished paper, 'On the pressures which sustain a heavy body in equilibrium when the points of support are more than three' by Charles Bonnycastle Bonnycastle discusses the problem of pressures that elevate a heavy body with more than three points of support, describing the importance of this knowledge in estimating the strength of bridges and building materials. Includes one page of figures. Subject: Physics / Engineering Written by Bonnycastle in Woolwich Common [London]. Communicated by Sir Jos [Joseph] Banks. Read to the Royal Society on 11 March 1819. Whilst this paper was not abstracted in the Proceedings of the Royal Society, a mention of its reading at a meeting of the Society was published in the Annals of Philosophy: 'Article III. Proceedings of Philosophical Societies'. Annals of Philosophy, vol 13, no 76, 1819, p. 307. 26 October 1818