§ XXIX. 3. Such groups, consolidated by a small square in their centre, form the shafts of St. Zeno, just spoken of, and figured in Plate XVII., which are among the most interesting pieces of work I know in Italy. I give their entire arrangement in Fig. XVIII.: both shafts have the same section, but one receives a half turn as it ascends, giving it an exquisite spiral contour: the plan of their bases, with their plinth, is given at 2, Plate II.; and note it carefully, for it is an epitome of all that we observed above, respecting the oblique and even square. It was asserted that the oblique belonged to the north, the even to the south: we have here the northern Lombardic nation naturalised in Italy, and, behold, the oblique and even quatrefoil linked together; not confused, but actually linked by a bar of stone, as seen in Plate XVII., under the capitals. [Illustration: Fig. XVIII.] 4. Next to these, observe the two groups of five shafts each, 5 and 6, Plate II., one oblique, the other even. Both are from upper stories; the oblique one from the triforium of Salisbury; the even one from the upper range of shafts in the façade of St. Mark's at Venice.[45] § XXX. Around these central types are grouped, in Plate II., four simple examples of the satellitic cluster, all of the Northern Gothic: 4, from the Cathedral of Amiens; 7, from that of Lyons (nave pier); 8, the same from Salisbury; 10, from the porch of Notre Dame, Dijon, having satellites of three magnitudes: 9 is one of the piers between the doors of the same church, with shafts of four magnitudes, and is an instance of the confusion of mind of the Northern architects between piers proper and jamb mouldings (noticed farther in the next chapter, § XXXI.): for this fig. 9, which is an angle at the meeting of two jambs, is treated like a rich independent shaft, and the figure below, 12, which is half of a true shaft, is treated like a meeting of jambs.