The central point in D’Agostino’s reflection about the history of instrumentation was to leave the areaArea of antiques and collecting to become an integral part of research in the History of ScienceHistory of science, guided by specific historiographical thesis. For a long timeTime, ‘theoreticismTheoreticism’ had characterized historian’s interest. In the second half of the twentieth century alongside a naïve empiricism widespread especially in scientific circlesCircles, the theory-ladennessTheory-ladenness of observables had driven research in the history of scienceScience. D’Agostino’s analysisAnalysis of Hertz’s experiment on electromagnetic waves was paradigmatic of a new historiographyHistoriography. From one hand Maxwell had considered the numerical equality between the speed of light and the ratio of absolute units of electrical quantities, obtained with electromechanical instrumentation, to be fundamental for his theory. Hertz, on the other hand, had succeeded in his purpose of detecting electromagnetic waves only by abandoning electromechanical instrumentation, and giving centrality to the resonator. In recent years Hanson and Amsterdamski provided a historiographical background for D’Agostino’s analysisAnalysis about the relationships between History of scienceHistory of science and History of the instrumentation.