This work covered centuries.  The earliest date of the ornamental work in Siena is 1369.  From 1413 to 1423 Domenico del Coro, a famous worker in glass and in intarsia, was superintendent of the works.  The beauty and spirit of much of the earlier inlay have been impaired by restoration, but the whole effect is unique, and on so vast a scale that one hesitates to criticize it just as one hesitates to criticize the windows at Gouda.

One compartment of the floor is in genuine mosaic, dating from 1373.  The designer is unknown, but the feeling is very Sienese; Romulus and Remus are seen in their customary relation to the domesticated wolf, while the symbolical animals of various Italian cities are arranged in a series of circles around this centrepiece.  One of the most striking designs is that of Absalom, hanging by his hair.  It is in sharp black and white, and the foliage of the trees is remarkably decorative, rendered with interesting minutiae.  This is attributed to Pietro del Minella, and was begun in 1447.

A very interesting composition is that of the Parable of the Mote and the Beam.  This is an early work, about 1375; it shows two gentlemen in the costume of the period, arguing in courtly style, one apparently declaiming to the other how much better it would be for him if it were not for the mote in his eye, while from the eye of the speaker himself extends, at an impossible angle, a huge wedge of wood, longer than his head, from which he appears to suffer no inconvenience, and which seems to have defied the laws of gravitation!

The renowned Matteo da Siena worked on the pavement; he designed the scene of the Massacre of the Innocents—­it seems to have been always his favourite subject.  He was apparently of a morbid turn.

In 1505 Pinturicchio was paid for a work on the floor:  “To master Bernardino Pinturicchio, ptr., for his labour in making a cartoon for the design of Fortune, which is now being made in the Cathedral, on this 13th day of March, 12 Lires for our said Master Alberto.”  The mosaic is in red, black, and white, while other coloured marbles are introduced in the ornamental parts of the design, several of which have been renewed.  Fortune herself has been restored, also, as have most of the lower figures in the composition.  Her precariousness is well indicated by her action in resting one foot on a ball, and the other on an unstable little boat which floats, with broken mast, by the shore.  She holds a sail above her head, so that she is liable to be swayed by varying winds.  The three upper figures are in a better state of preservation than the others.

[Illustration:  DETAIL OF PAVEMENT, SIENA; “FORTUNE,” BY PINTURICCHIO]

There was also in France some interest in mosaic during the eleventh century.  At St. Remi in Rheims was a celebrated pavement in which enamels were used as well as marbles.  Among the designs which appeared on this pavement, which must have positively rivalled Siena in its glory, was a group of the Seven Arts, as well as numerous Biblical scenes.  It is said that certain bits of valuable stone, like jasper, were exhibited in marble settings, like “precious stones in a ring.”  There were other French pavements, of the eleventh century, which were similar in their construction, in which terra cotta was employed for the reds.