n 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 facade of St. Mark's at Venice.[45]

Sec. 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,
Sec. 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.

All these four examples belonging to the oblique or Northern system, the
curious trefoil plan, 3, lies _between_ the two, as the double
quatrefoil next it _unites_ the two. The trefoil is from the Frari,
Venice, and has a richly worked capital in the Byzantine manner,--an
imitation, I think, of the Byzantine work by the Gothic builders: 1 is
to be compared with it, being one of the earliest conditions of the
cross shaft, from the atrium of St. Ambrogio at Milan. 13 is the nave
pier of St. Michele at Pavia, showing the same condition more fully
developed: and 11 another nave pier from Vienne, on the Rhone, of far
more distinct Roman derivation, for the flat pilaster is set to the
nave, and is fluted like an antique one. 12 is the grandest development
I have ever seen of the cross shaft, with satellite shafts in the nooks
of it: it is half of one of the great western piers of the cathedral of
Bourges, measuring eight feet each side, thirty-two round.[46] Then the
one below (15) is half of a nave pier of Rouen Cathedral, showing the
mode in which such conditions as that of Dijon (9) and that of Bourges
(12) were fused together into forms of inextricable complexity
(inextricable I mean in the irregularity of proportion and projection,
for all of them are easily resolvable into simple systems in connexion
with the roof ribs). T