Egnazio Danti, Vsus et tractatio gnomonis magni, quem Bononia ipse in dive Petronii templo ex illustrium senatorum comitis Joannis Pepuli perpetui illius fabricae praesidis et collegarum autoritate confecit a.D. MDLXXVI mense Apr. ad amplissimum senatum Bononiensem
Bologna 1576? 2°, p. 1, ill.; 40,3x28,8 cm Private collection
Extremely rare sheet published by the Medicean cosmographer to illustrate the functions of the gnomon of San Petronio in Bologna.