Paper, 'An account of some observations made in London by Mr George Graham and at Black River in Jamaica by Colin Campbell concerning the going of a clock in order to determine the difference between the lengths of isochronal pendulums in those places' Observes the differences in the swing of the pendulum of the same length at different latitudes, 60 years after the discovery of the phenomena by Mr. Richer. Subject: Mechanics Published in Philosophical Transactions as 'An account of some observations made in London, by Mr. George Graham, F. R. S. and at Black-River in Jamaica, by Colin Campbell, Esq; F. R. S. concerning the going of a Clock; in order to determine the difference between the lengths of isochronal pendulums in those places. Communicated by J. Bradley, M. A. Astr. Prof. Savill. Oxon. F. R. S.' Communicated by J [James] Bradley to the Royal Society on 6 December 1733 1733