Under the circumstances it was felt that some new material must be
devised to meet the requirements. Already Paul E. Denneville had been
successful in working with material made in imitation of Travertine
marble, used in many of the ancient buildings of Rome, very beautiful
in texture and peculiarly suited to the kind of building that needed
color. He it was who had used the material in the Pennsylvania Station,
New York, in the upper part of the walls. After a good deal of
experimenting Denneville had found that for his purpose gypsum rock was
most serviceable. On being ground and colored it could be used as a
plaster and made to seem in texture so close to Travertine marble as to
be almost indistinguishable. The results perfectly justified his faith.
As the palaces rose from the ground, making a magnificent walled city,
they looked solid and they looked old and they had distinct character.
Moreover, through having the color in the texture, they would not show
broken and ragged surfaces.



The Color Scheme



For the color-effects it was felt that just the right man must be found
or the result would be disastrous. The choice fell on Jules Guerin, long
accepted as one of the finest colorists among the painters of his time.
He followed the guidance of the natural conditions surrounding the
Exposition, the hues of the sky and the bay, of the mountains, varying
from deep green to tawny yellow, and of the morning and evening light.
And he worked, too, with an eye on those effects of illumination that
should make the scene fairyland by night, utilizing even the tones of