Search Loci: Convergence:
[Statistics are] the only tools by which an opening can be cut through the formidable thicket of difficulties that bars the path of those who pursue the Science of Man.
Pearson, The Life and Labours of Francis Galton, 1914.
Qadi Zada al-Rumi's Geometry
This is page 14 from the Geometry (1412) of Qadi Zada al-Rumi (1364-1436). Al-Rumi's book was a commentary on the Fundamental Theorems, written by al-Samarqandi (1250-1310), where he discusses twenty-five of Euclid's propositions in detail. The book shown in the image is a later copy of al-Rumi's work, probably written in the sixteenth century. At the top of the page is a discussion of Euclid's Proposition I-5, the "Bridge of Asses" proposition that the base angles of an isosceles triangle are equal. At the bottom, there is a discussion of I-6, the converse of I-5. Al-Rumi was an astronomer and mathematician in the court of Ulugh Beg (1393-1449) in Samarkand. He and his colleagues compiled the first complete star catlogue since the time of Ptolemy.