
The study of the subjective experience of time constitutes a classical research program of experimental psychology developed in many European laboratories during the first half of the twentieth century. Investigations of this kind were conducted also in Italy with research developed during the twenties in the psychological laboratory of the Institute of Higher Studies in Florence. In this context Enzo Bonaventura made an original contribution that was recognized and discussed also on an international level. The present paper would like to illustrate the theoretical methodological approach elaborated, and the results achieved, by this Italian researcher, with particular reference to the experimental techniques and instruments that he designed and created for this purpose. The experimental methodology in the study of the experience of time required the use of particularly precise instruments, by means of which it would be possible to arrive at the measurement and acquisition of quantitative data. In his study of the temporal experience, the Italian psychologist concentrated his attention especially on the presenting in succession of visual or auditory stimuli - all comprised in different comprehensive brief temporal intervals - and on the measure of the perceived temporal experience of time which the subject referred with an introspective act. The tachistoscope was the prince of instruments in this type of research, since it offered the possibility of presenting a visual stimulus for a very brief and measurable time. From the comparison between the classical tachistoscope, widespread in the European laboratories since the time of Wundt, and that modified by Bonaventura, there emerge substantial differences, not only and not so much on account of their diverse capabilities of performance, but especially because of the differences in the theoretical models and investigative objectives underlying such instruments.