Commentary on An Enquiry into the Nature and Origin of Literary Property (1762)

One of a number of published commentaries contributing to the mid-eighteenth century debate concerning the nature of literary property. The author of An Enquiry sought to repudiate the concept of a natural authorial property right existing at common law. In so doing, he specifically engaged with various aspects of William Warburton's earlier commentary (see: uk_1747), as well as presenting arguments that drew upon the nature of property in general, the differences between the right claimed by proponents of the common law right and other acknowledged incorporeal properties, the similarities between patents and copyright, the history of literary property, the experience of other jurisdictions (drawing upon Venice in particular), and the consequences that would follow from conceding the existence of a perpetual right both for authors in particular and society in general. This commentary, in turn, drew its own response in the guise of A Vindication of the Exclusive Rights of Authors, to their own work (1762).

The concept of transport capacity and its use in different geomorphic process domains

The notion of sediment-transport capacity has been engrained in geomorphological and related literature for over 50 years, although its earliest roots date back explicitly to Gilbert in fluvial geomorphology in the 1870s and implicitly to eighteenth to nineteenth century developments in engineering. Despite cross fertilization between different process domains, there seem to have been independent inventions of the idea in aeolian geomorphology by Bagnold in the 1930s and in hillslope studies by Ellison in the 1940s. Here we review the invention and development of the idea of transport capacity in the fluvial, aeolian, coastal, hillslope, débris flow, and glacial process domains. As these various developments have occurred, different definitions have been used, which makes it both a difficult concept to test, and one that may lead to poor communications between those working in different domains of geomorphology. We argue that the original relation between the power of a flow and its ability to transport sediment can be challenged for three reasons. First, as sediment becomes entrained in a flow, the nature of the flow changes and so it is unreasonable to link the capacity of the water or wind only to the ability of the fluid to move sediment. Secondly, environmental sediment transport is complicated, and the range of processes involved in most movements means that simple relationships are unlikely to hold, not least because the movement of sediment often changes the substrate, which in turn affects the flow conditions. Thirdly, the inherently stochastic nature of sediment transport means that any capacity relationships do not scale either in time or in space. Consequently, new theories of sediment transport are needed to improve understanding and prediction and to guide measurement and management of all geomorphic systems.