Manuscript, 'De ratione temporis que grave labitur per rectam data duo puncta conjungentem, ad tempus bravissimum quo, vi gravitatis, transit ab horum uno ad alterum per arcum cycloidis' by [David] Gregory 'On the ratio of the time that a weight falls through a given line joining two points, to the shortest time at which, by the force of gravity, it passes from one of these to the other through the cycloidal arc'. Paper by David Gregory on the difference in time of a heavy body falling through a cord or the arc of a cycloid. Subject: Physics Published in Philosophical Transactions as 'De Ratione Temporis quo grave labitur per rectam data duo puncta conjungentem, ad Tempus brevissimum quo, vi gravitatis, transit ab horum uno ad alterum per arcum cycloidis' Read to the Royal Society on 17 March 1697 [1697]