Curiosity takes many forms. Although the author of this entertaining book – which is not so much a twin biography as a cultural companion to Restoration London – never quite acknowledges it, the curiosity of Samuel Pepys was of a rather different order to that of John Evelyn. While both were movers in the nascent Royal Society, Pepys rose to become its president whereas Evelyn went on to decline that honour. As a well-connected career civil servant, Pepys was valued by the members of the Royal Society principally as an administrator and defender of the organisation, which was being ridiculed in playhouses and pamphlets (even Charles II quipped that natural historians were indulging in pointless endeavours, such as learning how to ‘weigh ayre’). Evelyn was more typical of the early membership of the society. He undertook experiments himself and was presumably involved in testing a pioneering submersible device in which a man was kept underwater for half an hour in the wet dock at Deptford, where Evelyn lived.