This paper began with the evidence that da Vinci had a global conceptualization of the world in his youth, and would most likely have encountered Paolo Toscanelli
in his role in the leading bottega in Florence working at the Duomo at the same time as Toscanelli's gnomon.
Yet, our collective past is crowded with so many what-ifs that you can't but wonder what the world would have been had Christopher Columbus not followed the flawed cosmology of the Italian, Paolo Toscanelli
, and not sailed west from Spain in search of India.
The map below is based on a map drawn by Paolo Toscanelli in 1469.
1469: Paolo Toscanelli draws a map (see above) that shows Japan, China, India, and the Indies on the western side of the Atlantic Ocean.
Yet one of the distinctive features of geography as a new incipient type of knowledge was its necessary and essential links with practicality and application; whatever its mathematical roots in the university, geography from the start appeared as an applied science developing connections with learned humanistic circles outside the university such as that of Paolo Toscanelli
in Florence or the Portuguese monarchs' patronage of Jewish astronomers.
Scientists who participated in this work include Paolo Toscanelli
, the Dominican Egnatio Danti, the Jesuits Christopher Clavius, Francesco Mario Grimaldi, Giambattista Riccioli, and Honore Fabri, and finally Gian Domenico Cassini and his son Jacques.
So it was with the "navigation chart" drawn by the Florentine physician and astronomer, Paolo Toscanelli
in 1474, and a copy of which was later sent to Columbus.
started the trend with his fifteenth-century meridiana in the Florentine duomo, but its heyday occurred in the decades after Galileo.
21 It is now thought to have inspired Alberti's concept of artificial perspective as it surely influenced the great Florentine cosmographer Paolo Toscanelli
. (Regarding Alberti's dependence on Ptolemaic concepts see Gadol, especially 157-75.