From the Renaissance to the seventeenth century the phenomenon of tidal motion constituted one of the principal arguments of scientific debate. Understanding the times for high and low water was of course often essential for navigation, but local variations (which nowadays are attributed to currents, coastal configurations, prevailing winds, seabed shaping and other geographic characteristics) made an inductive approach impractical and precluded the possibility of constructing a universally valid model for predicting these times. Notwithstanding the complexity of the phenomenon and its practical import, however, the early-modern theory of tidal ebb and flow, as clearly emerges from Duhem's analysis, appears to be neither the result of the interpretation of empirical data, nor aimed to their prediction. Rather, the interest in tides was of a theoretical nature and was aroused particularly by their double nature, being at the same time variable and regular, terrestrial and astronomical.

The public place of science and technology in Britain underwent a dramatic change during the first half of the nineteenth century. At the end of the eighteenth century, natural philosophy was still on the whole the province of a relatively small group of aficionados. London possessed only one institution devoted to the pursuit of natural knowledge: the Royal Society. The Royal Society also published what was virtually the only journal dealing exclusively with scientific affairs: the Philosophical Transactions. By 1851, when the Great Exhibition opened its doors in Hyde Park to an audience of spectators that could be counted in the millions, the pursuit of science as a national need, its relationship to industrial progress were acceptable, if not uncontested facts for many commentators.

Biography and geography do not always sit easily together in historical narrative. With a few notable exceptions, due weight is rarely given to the significance of territorial features in tales of talented individuals. Biographers perhaps play down the untidy contingencies of civic, institutional and domestic spaces in order to present a historiographically coherent portrait of their subject. However, once the vicissitudes of environment and everyday life are taken into account, the identity and accomplishments of the ‘great individual’ begin to merge inextricably with the vagaries of local politics and fluid socio-cultural alliances. For a figure with as formidable a posthumous reputation as T. H. Huxley, such a deconstruction might, at first, seem mundane and of little scholarly value. Yet there is considerable evidence that Huxley was not always successful in his efforts to gain power and influence within the many and varied sites of his working environments. Careful scrutiny of such evidence will show new perspectives on Huxley's complex career in Victorian London. It will also document problems in the construction of the South Kensington suburb as a credible site and fruitful resource for Huxley's remarkably diverse activities in education and science.

1831 was a momentous year for Charles Darwin. He passed his BA examination on 22 January, stayed up in Cambridge for two further terms and returned to The Mount, his home in Shrewsbury, in mid-June. On 6 August he left Shrewsbury with Adam Sedgwick for a geological field trip to North Wales, and after his lone traverse over the Harlech Dome returned to The Mount on Monday 29 August to find letters from John Stevens Henslow and George Peacock inviting him to joint HMS Beagle. This geological field trip was crucial for his work on the Beagle. For example, when he began his first geological work of the voyage on Quail Island, he was by that time a competent geologist. Though others have studied the North Wales tour in some detail, there is also another earlier and much briefer episode to consider. Darwin appears to have geologized on his own at Llanymynech in July. The contrast between his first recorded attempts at Llanymynech in July 1831 and then elsewhere in North Wales in August 1831 is most instructive, as his development as a geologist can be followed in his field notes. Retracing his steps today, and comparing his measurements and observations with new ones, throws light on what he might have learnt at different points during that summer.