a transit of Venere observation in Napoli

Dear Friends, at my site http://www.nicolaseverino.it updated today, you can see a rare document of observation of Transit of Venere done by Niccolò Maria Carcani in Neapolis on June, 6, 1761 from "Reale Collegio delle Scuole Pie". This document report the observating measurements and description

RE: Reverse-engineering oldest SGS

Thanks Chris.   This looks like a simple direct solution. Measure SH and SD. Calculate the design latitude from Sin Lat = Cos SH x Cos SD, and then the design wall declination from Sin Dec = Tan SD * Tan Lat. This works when the gnomon is still in place and you can measure SD and SH   I w