This volume looks at the way in which the development of a viable instrument technology has lain at the heart of astronomical research since the late-16th century. In particular, the concern with precise measurement has largely transcended the concern for purely philosophical considerations in establishing characteristics of the solar system. These articles, therefore, demonstrate how scientists like Tycho, Flamstead, Herschel, Lassell and Aimy recognised the importance of hypothesis, whilst acknowledging that hypothesis needed physical substantiation to produce inductive science.