> Metatheory > History of the Field > arghXiv:2608.03771
Reconstruction of a Nineteenth-Century Mechanical Cosmography from Published Plates
Abstract: A mechanical model of the cosmos built in the 1860s survives only in a set of engraved plates. We reconstruct its gear train from the plates and report that the model reproduces the apparent motions to within the accuracy of naked-eye observation, as its makers claimed. We further report that the gear ratios are those obtained by fitting the model to a published almanac, and that the almanac in question was computed on assumptions the model was built to displace. The makers recorded the fit as a confirmation. We record it as a fit, and note that we are able to distinguish the two only because the almanac survives.