One of the marble columns was evidently replaced, some hundreds of years ago, by another of inferior marble, which has stood the test of time very badly; it is much worn, but its sculpture is very interesting. Here we see a real old tournament of the Middle Ages; two knights clad in full chain armour, tunic and helmets entirely chain, and the latter decorated with flowing plumes. The shields are splendid, and the anatomy of the fighting warriors worthy of Rubens. On this column we also discern some strange monsters such as we read of in “Geoffery the Knight” when we were children. All the capitals of the _Pórtico de Gloria_ are covered with rich sculpture; that above the seated figure of St. James is decorated with a representation of the Temptation in the Wilderness, to the north we see Satan tempting our Saviour to turn stone into bread, to the west we see Christ on the pinnacle of the temple, to the south is Satan showing Christ all the glories of the world, and holding in his hands a scroll with the words _Haec omnia Tibi dabo, si cadens adoraveris me_, and Christ holds His scroll with the words _bade Satana_; on the fourth and eastern side, facing the interior of the cathedral, we see angels ministering unto Christ. Lopez Ferreiro[158] has devoted a most interesting chapter to the execution of the work in the _Pórtico de Gloria_. He shows how Mateo, the architect, subordinated everything else to the one grand principle of unity; thus following the supreme law in artistic production. We do not see anywhere in Greek or Roman sculpture, as Viollet le Duc has pointed out, a tympanum covered with statues the attitudes and size of which are adapted to its shape. The façade of _Notre Dame de Paris_ has a tympanum crowded with statues, but there the tympanum is divided into four distinct parts; that of Santiago is unbroken. But unity alone is not enough to constitute an aesthetic work of art; variety is also needed in order to exclude monotony. In the _Pórtico de Gloria_ there are hardly two figures to be found in the same attitude. Let us look at the four-and-twenty elders. Each of the old men has his feet in a different attitude; he has his own way, too, of handling his musical instrument. Mateo had the art of making his statues look perfectly easy and natural even when represented in the most difficult postures. There is a look of spontaneity about the placement of their limbs. Ferreiro has noted the capricious manner in which the legs of the fifth old man are covered; we feel instinctively that he has only just this minute crossed them, and that a moment ago he had them in quite another position! We see the same variety in the flow or curl of the hair, in the shape and size of the beard. All bear witness to the zeal with which Mateo worked to produce a natural and lifelike effect, and to evade the least suspicion of convention or routine. We have seen how the artist of the _Puerta de las Platerias_ attempted to do this, but in his day no