Photos, old glass plates, negative - positive, 4 photos taken in Venice,

Set of 4 authentic and original photos, taken in venice by my ancestors around 1900. Height: 13x18 cm. Each view is framed in a brass frame with patinated gilding, period. The fountain and the courtyard of the doge's palace, The canal and the bridge of sighs, ponte dei sospiri. Baldassare longhena, the church of santa maria della salute in venice. Negative plates - positive.