According to a dominant view in the scholarly literature, Musschenbroek is to be considered a follower of Newton’s methodology, i.e. as a natural philosopher who, although he occasionally departed from Newton’s doctrines, aligned himself to Newton’s methodological views. Few scholars have, however, explained in full detail what it means to claim that Musschenbroek followed Newton’s method. The purpose of this essay is to get more grip on this matter.

The total solar eclipse of 18 August 1868 was one of the most important eclipses in the history of solar physics, and observations of it led to a new understanding of the nature of the chromosphere, prominences and the corona. Among other places, this eclipse was visible from the Dutch East Indies (present-day Indonesia). Soon after the 1868 event came the total solar eclipse of 12 December 1871, which also was visible from the Dutch East Indies and offered a further opportunity to build on the achievements of 1868. Both solar eclipses were observed from the Dutch East Indies by teams led by J.A.C. Oudemans, and in this chapter we provide biographical details of Oudemans before examining the scientific instruments used and observations made in 1868 and 1871 by Oudemans and other local observing teams. We end by assessing the international importance of Oudemans’ published scientific results.