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.

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.

In this article we throw more light on Einstein's position as a pacifist and democrat during World War I than was possible up to now. This results from a systematical search for and evaluation of published and unpublished documents. Among others, it was possible to give evidence of Einstein's radicalization and to clear up the circumstances of his public appearance during the troublesome days of the Revolution in November 1918. Einstein's role in the Bund Neues Vaterland and other pacifist organizations and his interaction with other pacifists in Germany and abroad is exposed in detail and interpreted. In contrast to the generally accepted view, we give a reappraisal of Einstein's activity and show that his pacifism was always of a humanitarian nature. He only rarely applied social and political categories to the happenings during the war. Due to his main focus on physics Einstein's pacifism remained one more of creed than of deed.

This name is given to any collection of similar individuals of the same nature which exist, although we can observe only some of these individuals, and never the entire collection of all at the same time.

Most lay users of statistics think in terms of means (averages), variances or the square of the standard deviation, and Gaussians or bell-shaped curves. Such conventions are entrenched by statistical practice, by deep mathematical theorems from probability, and by theorizing in the various natural and social sciences. I am not claiming that the particular conventions (here, the statistics) we adopt are arbitrary. Entrenchment can be rational without its being as well categorical (excluding all other alternatives), even if that entrenchment claims also to provide for categoricity. 1 provide a detailed description of how a science is “normal” and conventionalized. A characteristic feature of this entrenchment of conventions by practice, theorems, and theorizing, is its highly technical form, the canonizing work enabled by apparently formal and esoteric mathematical means.