Unpublished manuscript, 'On the pressures which sustain a heavy body in equilibrium when the points of support are more than three' by Charles Bonnycastle Bonnycastle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. Deletions and corrections appear throughout in ink and graphite. 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