Unpublished paper, 'On the extension of the value of the ratio of the circumference of a circle to its diameter to 440 places at decimals' by William Rutherford Rutherford shares mathematical formulae for calculating pi to 440 decimal places. Annotations in pencil throughout. Subject: Mathematics Received 17 November 1852. Communicated by Samuel Hunter Christie. Written by Rutherford at the Royal Military Academy [Woolwich, London]. Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 6 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'On the extension of the value of the ratio of the circumference of a circle to its diameter'. 4 October 1852