Joseph Priestley: the man who drew time

The Joseph Priestley House Museum at Northumberland, Pennsylvania became interested in Priestley's pioneering timelines as a complement to his better known work in chemistry, electricity, biblical scholarship and political radicalism. Boyd Davis wrote this short article for the newsletter published by the Friends of the museum. The article concentrates on the connections between Priestley, his French contemporary Barbeu-Dubourg and Benjamin Franklin at the time of the struggle for American Independence, and Priestley's two key chronographic innovations: the use of drawn or printed lines to represent the duration of lives, and the associated use of dots to show when the dates of such lives are in doubt or dispute. Keywords: timeline, chronographic

Book review. Cartographies of Time: a history of the timeline

A review of 'Cartographies of Time: a history of the timeline' by Daniel Rosenberg and Anthony Grafton. Princeton, NJ: Princeton Architectural Press, 2010. (272pp. ISBN: 9781568987637)

Time machines.

The chapter is concerned with the use of computers to represent historical time visually, typically as ‘timelines’. Research into the sophisticated practice and theory of early modern paper timelines in the eighteenth century reveals the weakness of current practice, especially on the Web. Behind the work of the early pioneers lay a vision of mechanising knowledge. At that time, this proved a productive metaphor, but in our own time the mechanistic properties of computers have tended to encourage an approach to visualising history that excludes all but the crudest aspects. Solutions are needed which use computing in ways that do justice to the demands of historiography

Mapping the unseen: making sense of the subjective image.

It used to be thought that photography, as a kind of automatic mapping, could provide an objective view of the world. Now we are aware of the power of framing and other interventions between what is 'out there' and what is captured in depiction. Perhaps even perception, let alone depiction, shares this subjectivity? The Sapir-Whorf hypothesis holds that different cultures actually see the world in different ways, as evidenced and influenced by concepts in their languages – though this idea has been derided, for example by Pinker. A key difficulty is that the word subjectivity is bandied about without care for its different meanings and without distinguishing the many forms it takes in the graphic image. If into this muddle we introduce the idea of interactivity, still greater confusion easily follows. The chapter brings some order to different kinds and levels of subjectivity by documenting how they are reflected in forms of graphical mapping. In the process, it becomes clear how significant is the change in media technologies from those bound by the conventional rectangles of the page and screen to media which are interactive, pervasive, multimodal, physical and social

'Scratch' locative audio drama - report to BBC executives on trial at BBC FreeThinking 2008

‘Scratch’ investigates the use of physical space as a representation of narrative and dramatic structure. An audio-drama, it is a world-first in being location-sensitive without being tied to any particular place (preceding attempts by others have emphasised location-specific aspects of the genre). Developed in collaboration with and part-funded by BBC Radio Drama, it builds on research undertaken for ‘Dragons’ (output 4). It uses pre-recorded audio on GPS-enabled mobile devices allowing sounds to be virtually attached to locations in an outdoor space. As participants move, they encounter scenes forming a coherent drama which behave differently if the same place is visited more than once. This translocational approach opens novel artistic possibilities exploited through team expertise in narrative, sound design and advanced interaction. It is also significant in the economics of broadcast media as a more viable proposition than the many experimental locative experiences which have been site-specific: this was of great interest to the BBC. The public performance selected for BBC FreeThinking, 1-2 September 2008 in Liverpool as part of European Capital of Culture was reported in a co-authored 2009 conference presentation at ISEA, Belfast, 26-29 August 2009 and in a co-authored short chapter in Spierling and Szilas (eds.) Interactive Storytelling, Springer 2008. Boyd Davis directed the project and devised and undertook the evaluation with 40 trial listeners, reporting to BBC executives (http://researchonline.rca.ac.uk/1000/) for whom a second trial was also run in London in 2009. The evaluation used interview, video observation and a questionnaire combining an open question at the beginning with more specific questions later, avoiding channelling respondents' reactions immediately after the experience into issues which might not be uppermost in their minds, while also yielding data capable of rigorous analysis. The evaluation was to provide feedback to the makers of the drama and to guide policy at the BBC. [287] Participants were recruited principally through the publicity for FreeThinking 2008 – mainly via the festival website. The average age of participants was 40. The gender of participants was 20 males, 17 females and 3 null returns. The evaluation strategy was to combine an open question at the beginning with more specific questions later. In this way we avoided channeling respondents' initial opinions immediately after the experience into issues which might not be uppermost in their minds, while also yielding data capable of rigorous analysis. The purpose of the evaluation was to provide guidance for ourselves as the makers of the drama and to guide policy at the BBC on locative and other interactive media. The responses are analysed in the report

Hobby Farming - For Pleasure or Profit?

Hobby farms have represented a significant share of census-farms for many decades. Most operators of hobby farms treat the farm as a "hobby" -- there is no intention of making money. However, some hobby farms are profitable. The purpose of this paper is to identify the proportion of farms in Canada which are hobby farms and to identify the characteristics of the hobby farms that make money. According to 1991 Census of Agriculture data, there were 50,991 census-farms in which the main operator reported 190 days or more of off-farm work and whose farm did not employ any year round paid labour. Part-time or "hobby" farmers are an integral part of the agriculture population. Among the hobby farmers in Canada 40% are reporting positive net cash farm income. Only 9% of these hobby farmers are reporting net cash farm income of greater than $10,000. Ontario and BC's farm population consists of the highest proportion of hobby farms (18% and 16% respectively). Hobby farming is not a new phenomenon in Canada and hobby farmers do not appear to be a dying group. It is obvious that there is much more to this pursuit than making a profit.Farm Management,

Least-Squares Covariance Matrix Adjustment

We consider the problem of finding the smallest adjustment to a given symmetric $n \times n$ matrix, as measured by the Euclidean or Frobenius norm, so that it satisfies some given linear equalities and inequalities, and in addition is positive semidefinite. This least-squares covariance adjustment problem is a convex optimization problem, and can be efficiently solved using standard methods when the number of variables (i.e., entries in the matrix) is modest, say, under $1000$. Since the number of variables is $n(n+1)/2$, this corresponds to a limit around $n=45$. Malick [{\it SIAM J. Matrix Anal.\ Appl.,} 26 (2005), pp. 272--284] studies a closely related problem and calls it the semidefinite least-squares problem. In this paper we formulate a dual problem that has no matrix inequality or matrix variables, and a number of (scalar) variables equal to the number of equality and inequality constraints in the original least-squares covariance adjustment problem. This dual problem allows us to solve far larger least-squares covariance adjustment problems than would be possible using standard methods. Assuming a modest number of constraints, problems with $n=1000$ are readily solved by the dual method. The dual method coincides with the dual method proposed by Malick when there are no inequality constraints and can be obtained as an extension of his dual method when there are inequality constraints. Using the dual problem, we show that in many cases the optimal solution is a low rank update of the original matrix. When the original matrix has structure, such as sparsity, this observation allows us to solve very large least-squares covariance adjustment problems