'Diarium Observationum Astronomicarum Coelestium' ('Journal of astronomical observations of the heavens'): first notes of observations with the mural arc, 18 January 1694 - 16 March 1698, mainly in the hands of the assistants Samuel Clowes and James Hodgson, though Flamsteed's also appears, 180 folios. There are entries noting visits by Peter the Great (160r, 164v) and other national and personal events (e.g. 24r, 39r, 176r). Inside the back cover is a signed statement by Isaac Newton.