The Essays Presented In The Following Pages Are The Product Of No Hasty Thought. The Choice Of Illustrations Has Been Difficult. It Has Seemed Best, However, To Reproduce In Full The Little Known Sketches Of Bernini Showing The Development, In His Mind Of The Design For The Piazza Of St. Peter's, And The Sculptor's Models Wrought By His Own Hands. For The Rest I Have Thought That It Would Be More Serviceable For The Reader To Have A Few Typical Examples Illustrating The Main Points Of The Text Rather Than A Larger, And Perhaps More Confusing, Selection Of Subjects From The Almost Inexhaustible Wealth Of Available Material.