An interesting theory concerning the design of the palace, and incidentally a critical estimate of its architecture, has been given us by Mr. George Edmund Street in his scholarly treatise upon "Brick and Marble in the Middle Ages." "The whole design" he writes, "is divided into three stages in height. The upper is nearly equal to the united height of the two lower stages, and is faced entirely with a delicate diaper of marble cut into small oblong pieces, which look save in their texture and color, only too much like bricks. In this marble-faced wall are pierced a number of windows with pointed arches--the tracery of which has been taken out--and in or near the centre of each façade is a much larger window and a balcony, which look as though they had been subsequently inserted. The lowest stage consists of a long and uniform arcade of very simple pointed arches resting upon circular columns with elaborately carved capitals; these columns have been shortened by some twenty inches of their old height by the rise of the water and the consequent elevation of the pavement, to the great damage of their effect. The intermediate stage is a magnificent arcade supporting very vigorous tracery and divided from the stages above and below it by large and pronounced lines of carved and moulded string-courses. [Illustration: DUCAL PALACE DETAIL OF CEILING, ANTE CHAMBER OF THE CHAPEL] "It is important to observe that up to the top of the second string-course the whole of the architecture is of the very best kind of Venetian pointed, and is, I believe, the very best and truest specimen of Gothic architecture south of the Alps.