BRITAIN AND FRANCE. l6lH TO l8XH CENTURY

connect the two central columns of each side of the square, while
fragmentary vaults curve up from the three columns of each corner
of the square to form four more arches in the corners. Now, these
three corner columns on each side are also tied together by straight
entablatures, so that each of the four sides has a rhythm of straight
and low—arched and tall—straight and low. Here is a first ingenious

88. SIR CHRISTOPHER WREN: ST. STEPHENS, WALBROOK, LONDON, 1672-87,
interlocking of effects. Looking up the dome we perceive eight
arches of identical height, but looking straight in front of us
towards any one side of the square there is differentiation of the bays.
However, that is not all. The arched centres of the sides can also be
regarded as the entrances to four arms of a cross, a Latin cross, since
the tunnel-vaults of the south and north arms are v^ry shallow,
whereas the east arm with the altar has a somewhat longer cross-
vault, and the west arm one double the length of the altar arm. To
achieve that, the western arm consists of two bays separated by
columns in the normal manner of longitudinal churches. As these
columns are exactly identical- with all the other columns, the first
impression one receives on entering the church is one of a short nave
with aisles leading towards a dome of unaccountable width. To finish
the story, this seeming nave has narrow flat-ceilinged outer aisles as
well, and these outer aisles run right through to the east wall. Only
we cannot call them aisles., all the way through, because at one point
they rise into being the north and south arms of the cross and then sink
again to become chancel aisles. The inner aisles of course, one dis-
covers later, run into the wide crossing just as the nave. The whole
rectangle of the church is set out with sixteen columns altogether,
172