This paper deals with one of the first attempts to measure simple reactions in humans. The Swiss astronomer Adolph Hirsch investigated personal differences in the speed of sensory transmission in order to achieve accuracy in astronomy. His controversial results, however, started an intense debate among both physiologists and astronomers who disagreed on the nature of these differences. Were they due to different eyes or brains, or to differences in skill and education? Furthermore, they debated how to eliminate them. Some, for (...) example, wanted to eliminate the observer, and prescribed the use of new technologies like the electro-chronograph or photography, while others believed in discipline and education. By debating the nature of these differences, astronomers and physiologists sketched both different conceptions of ‘man’ and different paths to objectivity. These diverse conceptions, moreover, were tied to current nineteenth-century debates, such as the benefits or disadvantages of railroads, telegraphy and the standardization of time and longitudes. By focusing on the debates surrounding the speed of sensory transmission, this paper reevaluates the history of astronomy, physiology and experimental psychology. Furthermore, in investigating astronomy's relation to the human sciences, it uncovers profound connections in the traditionally separate histories of objectivity and the body.L'heure sera distribuée dans les maisons,comme l'eau ou le gaz.Adolph Hirsch. (shrink)

The ArgumentIt is often assumed that all sciences travel the path of increasing precision and quantification. It is also assumed that such processes transcend the boundaries of rival scientific disciplines. The history of the personal equation has been cited as an example: the “personal equation” was the name given by astronomers after Bessel to the differences in measured transit times recorded by observers in the same situation. Later in the nineteenth century Wilhelm Wundt used this phenomenon as a type for (...) his experiments on reaction times. For historians of psychology, this has been taken to be an exemplary case where quantified laboratory science rescued astronomy by showing that this was really a psychological phenomenon measurable only in complication experiments. This paper challenges this story. Astronomers neither ignored, nor despaired of, the personality problem. Instead, the managers of the great observatories developed a new chronometric regime of vigilant surveillance of subordinate observers. The astronomers' solution was thus intimately connected with social and material changes in their way of life: a division of labor in the observatories, a network of observing sites, a mechanization of observation. The paper documents these changes and then presents a study of one case where managers, amateurs, and psychologists clashed for authority over the personality problem. Measurement is given its meaning when situated in specific contexts of styles of work and institutions. Disciplines give meanings to values, and often resist attempts by others to redefine these meanings or to gain authority over measurement. Quantification is not a self-evident nor inevitable process in science's history, but possesses a remarkable cultural history of its own. (shrink)

A prominent feature of late nineteenth-century psychology was its intense preoccupation with precision. Precision was at once an ideal and an argument: the quest for precision helped psychology to establish its status as a mature science, sharing a characteristic concern with the natural sciences. We will analyse how psychologists set out to produce precision in 'mental chronometry', the measurement of the duration of psychological processes. In his Leipzig laboratory, Wundt inaugurated an elaborate research programme on mental chronometry. We will look (...) at the problem of calibration of experimental apparatus and will describe the intricate material, literary, and social technologies involved in the manufacture of precision. First, we shall discuss some of the technical problems involved in the measurement of ever shorter time-spans. Next, the Cattell-Berger experiments will help us to argue against the received view that all the precision went into the hardware, and practically none into the social organization of experimentation. Experimenters made deliberate efforts to bring themselves and their subjects under a regime of control and calibration similar to that which reigned over the experimental machinery. In Leipzig psychology, the particular blend of material and social technology resulted in a specific object of study: the generalized mind. We will then show that the distribution of precision in experimental psychology outside Leipzig demanded a concerted effort of instruments, texts, and people. It will appear that the forceful attempts to produce precision and uniformity had some rather paradoxical consequences. (shrink)