Wolfgang Sartorius Von Waltershausen was a famous German geologist and astronomer who lived in 1800. His Der Aetna, recently translated from German, could be defined as the first truly scientific-volcanological treatise on Etna. Split into three volumes, it contained very accurate drawings of many areas of the Valle del Bove (now no longer visible because it was covered by recent eruptions) and of the summit craters. His descriptions of the eruptive phenomena still have scientific value today, as does the terminology used.
The volumes also contain more or less direct evidence of the 1669 eruption, which led to an accurate description of the event and its final stages: Wolfgang Sartorius Von Waltershausen collected evidence and precise measurements of the collapse at the summit craters in the final stages of this eruption.