The need for blade tip clearance instrumentation has been intensified recently by advances in technology of gas turbine engines. A new laser-optical measurement system has been developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in rotating component rigs and complete engines. The system is applicable to fan, compressor and turbine blade tip clearance measurtients. The engine mounted probe is particularly suitable for operation in the extreme turbine environment. The measurement system consists of an optical subsystem, an electronic subsystem and a computing and graphic terminal. Bench tests and environmental tests were conducted to confirm operation at temperatures, pressures, and vibration levels typically encountered in an operating gas turbine engine.

In an earlier issue of the International Review for the Sociology of Sport, Eugen König argued that doping exposes sport as an enterprise which is inherently exploitative (1995). Doping is consistent with other practices and technologies which push human limits of performance but which are arbitrarily included as part of `pure', `natural', and `authentic' sport only because they are not against the rules. By circumscribing what is to count as ethical inquiry in sport within a discussion of obligations in relation to proscriptive rules, sport ethicists cannot avoid being complicit in supporting a sport culture that is often harmful to athletes. König charges that a sport ethics that concerns itself only with questions that emanate from rule breakage `does not deserve the name of ethical criticism' and is `a powerless protest against sport' and `actually prevents what it pretends to intend' (1995: 256). We take König's critique of sport ethics seriously and, through this commentary, we aim to initiate a discussion about a new sport ethics that would have quite different pedagogical, political and scholarly tasks. The discussion is situated in the ethics of French intellectual, Michel Foucault, and contextualized in the proliferation of ethical concerns and debates within contemporary Canadian sports discourse.

In this essay Maureen Ford examines a selection of situated knowledges discourses in order to make explicit their attention to political effects. She contends, first, that the “epistemic public(s)” constituted through these discourses are multiple, interactive, performative, and layered, and further that they are explicitly political in ways that are denied by standard epistemological approaches. Furthermore, Ford maintains that the political effects circulated within standard and situated knowledges are epistemologically and educationally significant. Attending to the work of Donna Haraway, Patricia Hill Collins, and María Lugones, she teases out some of the various strategies through which their texts explicitly invoke politically salient, multidimensional, embodied engagement with spaces, people, and discourses in order to make sense. Ford explores the ramifications for educators and educational theorists of addressing such epistemic publics, noting that they are complex and almost inevitably uncomfortable. Taking up discourses of situated knowledges, she suggests, proliferates the avenues through which educators and educational theorists can contribute to the creation and contestation of “public” truths.

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