The accounts of early travellers are often enlivened by the side issues, the odd observations, and in the case of edited and translated books, the footnotes. Gibbon was famous for the interest in his footnotes, and  many an editor hasn’t been able to resist wry or critical comments. The published account of his voyage to China in 1750 by the Swedish naturalist Pehr Osbeck was translated, itself from a German translation, the German, then English naturalist Johann Forster. Forster included a handful of footnotes, a couple of which, including weird views of swallows hibernating under water, can be found in the attached article.