Concrete practices: Testing in an earthquake-engineering laboratory

Successful testing depends upon projecting from a test situation to the per formance of a technology under working conditions. Some have argued that pr ojection is made possible primarily through a collective agreement that the test circumstances and working conditions are similar in crucial ways. Thi s paper argues that projection is better understood in many cases as a set of local practices through which testing produces change in a wider context of technology use. In the earthquake-engineering laboratory described here , this connection depends upon the circulation of skilled people, material objects and symbolic representations across distinct work settings, in such a way as to construct a continuous 'chain of practices' between the labora tory and the worlds of construction, academia and design engineering. This analysis highlights the importance of the division of labour in shaping tec hnical practice both inside and outside the laboratory.