These "azulejos", or wall tiles, were made, probably in Coimbra, to satisfy the instructions issued by the Superior-General of the Society of Jesus in 1692, aimed at the improvement of the quality of mathematics teaching in Portugal. However, recourse to visual memory also served astronomy and physics. The geometric figures were a faithful reproduction of the teaching version of "Elements", a work by Euclid, published in 1654 by the Jesuit André Tacquet. In 1836 the walls of the refectory of the College of Jesus, in Bahia, still sported tiles identical to these.