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Writhe measures the extent to which a curve is kinked and coiled about itself in space. It has generally been expressed as a double integral. This measure can be interpreted as the average number of signed crossings seen by each viewer, over all possible viewpoints of the curve. This simple geometrical interpretation is used to describe the established properties of the writhe, as applied to closed spacecurves. These descriptions differ from previous work as they do not require the construction of an artificial ribbon structure. A major feature of this thesis concerns the evaluation of the writhe along a preferred direction. A directional measure termed the polar writhe will be developed which can be applied to generic curves (open or closed) . This single integral expression is shown to be equivalent to the double integral writhe measure for closed curves. However for open curves the two measures are shown to differ. Further, it is shown that the polar writhe has distinct advantages when analysing curves with a strong directional bias. The thesis then discusses in detail the properties of both the writhe and the polar writhe measures for open curves. The use of artificial closures for both measures is examined. In the case of the writhe a new closure is defined that allows the evaluation of the writhe using single integral expression via the theorems of Fuller. This closure is unique in that it can be applied to open curves whose end points are in general position. A simple expression for calculating the non-local polar writhe is derived which generalises a closed curve expression defined in (Berger Prior J. Phys. A: Math. Gen. 39, 8321-8348, (2006)). A quantitative study on the effect of the choice of evaluation direction of the polar writhe is conducted. The polar writhe formulation is applied to a simple linear force-free magnetic field model where the field lines form loops above a boundary plane. Loops with a sufficient amount of kinking are generally seen to form S or inverse S (Z) shaped structures. Such field lines structures are commonly observed in the Sun’s corona. A popular measure of the field line morphology is the magnetic helicity. We use the polar writhe, the correct form for the writhe helicity in the coronal region, to challenge some popular assumptions of the field. Firstly, the writhe of field lines of significant aspect ratio (the apex height divided by the foot point width) can often have the opposite sign to that assumed in a recent review paper by Green et al (Solar Phys., 365-391, (2007)). Secondly, we demonstrate the possibility of field lines forming apparent Z shaped structures which are in fact constructed from a pair of S shapes and have a writhe sign expected of an S shaped structure. Such field lines could be misinterpreted without full knowledge of the line’s three dimensional structure. Thirdly, we show that much of the interesting morphological behaviour occurs for field lines located next to separatrices.

Throughout the British Mandate for Palestine (1920-1948), British women travelled to the country as missionaries, teachers, welfare workers, nurses, doctors, journalists and colonial wives. Their actions affected the lives of the people of Palestine and tell us much about the nature of British colonialism in this settler colonial context. In the existing historiography of the Mandate, a male-dominated narrative prevails, with British women receiving very little attention from historians. This is the first extensive study of these British women. It uses their correspondence, reports and publications, archived across Britain, Israel, the occupied Palestinian territories, Beirut, and Washington, D.C., to analyse their activities in various spheres of the intimate. The attitudes and actions of these women expose the variability of the colonial encounter in this setting. In Mandate Palestine, British women's intimate colonialisms were multiple: there existed an intrusive intimacy of condescension towards the Palestinian Arab community and a paradoxically distant intimacy of respect towards the Jewish community. This was based on discourses of difference constructed by British women and underpinned by hierarchies of child-rearing, domesticity, agency and modernity, with the Jewish community typically placed further up these social scales than the Palestinian Arab community. There were however inconsistencies in, and limitations to, these multiple intimate colonialisms, which ultimately undermined the strength of British women's discourse. This thesis develops existing histories of British women in early to mid-twentieth century Palestine and contributes to enhanced understandings of the British Mandate for Palestine more broadly. By inserting British women in Palestine into existing imperial literatures on intimate colonialisms, this thesis establishes a new framework for grappling with the nature of white women's colonialisms in the juncture between colonial and settler colonial phenomena: the concept of multiple intimate colonialisms. This marks an important and original contribution to both colonial and settler colonial studies.

This thesis examines the long political career of Sir Halford Mackinder (1861-1947), the father of modern British geopolitics, underlining its crucial importance for the origins and evolution of the famous Heartland theory of 1904. Far from having a meta-historical significance, in fact, this elaborate geopolitical vision of Central Asia was the direct product of the cultural and strategic circumstances of the early twentieth century, reflecting Mackinder’s patriotic commitment to the cause of the British Empire, threatened by new powerful foreign rivals like Germany and the United States. Seriously concerned about the future of Britain’s international position, the Oxford geographer tried then to translate his brilliant educational talent in the political domain, supporting the tariff reform campaign of Joseph Chamberlain and fighting relentlessly for the political union of London with the overseas Dominions. Meanwhile he also focused his geographical imagination on the problem of India’s defence, developing a bold containment strategy against the territorial expansion of Russia in Asia. However, both these initiatives failed to influence the official policies of the British government, while the parliamentary career of Mackinder at Westminster knew more frustrations than successes, due to the internal divisions of the Unionist Party and to the bitter constitutional disputes of the last antebellum years. From this point of view, the outbreak of European hostilities in 1914 represented an important turning point for Mackinder’s political and intellectual life, compelling him to partially modify his previous imperialist ethos and to recognise the need of a more balanced and democratic international society at the end of the conflict. Expressed originally in Democratic Ideals and Reality, published in 1919, this new attitude toward international affairs found later its practical application in the activities of the Imperial Committees, successfully directed by Mackinder on cooperative lines for all the interwar years.