An examination of the carpentry and proportions of Cimabue's Croce Crucifix (Museo dell'Opera di Santa Croce, Florence) after the Florence Flood of 1966 while the painting was in restauro in the Laboratorio del Restauro in Florence. An analysis of the exact dimensions of the crucifix reveals that the super-structure was designed with a proportional system based on the square, and this pattern is shown to relate also to the monumental gabled altarpieces of Cimabue in Florence and in the S. Francesco altarpiece, Louvre, Paris. The analysis suggests that the Christ figure was designed as the homo quadratus, and the source for this and the proportional system is traced to Vitruvius De architectura. -- AATA