Edificorum altitudines quomodo aut per speculum planum aut aquam statem dimetiaris?; Fig. 1: Altimetry with a sun quadrant and water reflection; Fig. 2: Altimetry with a sun quadrant and mirror; Fig. 15; p. 42; 1533; Petrus Apian: Horoscopion Apiani generale dignoscendis horis cuiusqumque generis aptissimum [...]. His accedit distantia[rum]; altitudinum; & profunditatum per idem hoc instrumentum dimetiendarum ratio longe accuratissima & ingeniosa [...]. [Ingolstadt]: [Apianus]; [1533]