... and signs and the signs of signs are used only when we are lacking things.

Brother William of Baskerville in The Name of the Rose by Umberto Eco

Recreating, as part of doing history, can be a way of reflecting what creating is as part of science. Discussions revolving around historical understanding of the scientific enterprise have recently included strong commitments to turn scientific practice into one of the main objectives of historical study. One specific methodological approach to face up to this assignment is integrating the reconstruction and reperformance of past experiments into the historical analysis of the doing-part in science. This paper deals with the doing-part in history, that is, with the historiographical consequences that might stem from this reconstruction and reperformance of past experimentation. In the course of a four-month period of research I worked with a replica of the so-called ‘actinometer’, an instrument to measure the intensity of solar radiation, which was invented by John Herschel in 1824. On the basis of this example, I try to trace how recent performances of experimental activities can contribute to historical understanding of human agency in scientific practice.