4 CONCLUSIONS AND IMPLEMENTATION

It was concluded that many of Garnsey's finishes throughout the vast U.S. Custom House were mixed-media composites of complex layered structures, designed to compliment, reference and harmonize with associated marbles and breccias and patinated metalwork. The surviving original blue panels of the main hall provide some sense of the luminous trompe l'oeil effect that was possible with Garnsey's complicated and esoteric admixtures of media. However, because the media of these surviving finishes have darkened and become somewhat opaque, it is not possible to ascertain precisely the original appearances of the finishes. Similarly, so altered, damaged, and overpainted were most of the original architectural surfaces that exposure of Garnsey's finishes proved impossible in most instances. Where exposed, extreme shifts of tone and darkening were obvious.

Consequently, an exact replication of Garnsey's finishes was not judged possible in the U.S. Custom House. Rather, Garnsey's original five-color scheme for the architectural polychromy was specified to create an accurate general effect of the original interior decoration. Where confirmed by analyses, toned glazes were executed. Surviving original glazes, for example, from the vaults of the main hall, provided the models.8

The complex nature of Garnsey's finishes, their alteration of tone and deteriorated condition, made determination of the five base tones and glazes a complicated process that required a minimum of seven steps. Historic architectural finishes are customarily examined in cross section using reflected light microscopy to determine color matches, sometimes in conjunction with exposures of original surfaces in the building and pigment analyses. However, incorrect colors and an incomplete and incorrect understanding of Garnsey's remarkable decorative repertoire would have resulted without an integrated approach and extensive examination of the decorative finishes (table 1).

TABLE 1 GARNSEY'S PALETTE IN THE U.S. CUSTOM HOUSE: INITIAL AND FINAL IDENTIFICATION OF BASE COLORS

The U.S. Custom House, like so many outstanding historic buildings, is a structural work of art on a vast scale that incorporates the same component materials, execution techniques, and conservation problems that characterize other works of art. The procedures used to determine Garnsey's polychromy and other decorative finishes were developed for, and continue to evolve for, fine arts conservation. Thus, the roles for conservators in historic preservation and restoration projects must be viewed as indispensable, but separate from, those of architects, preservationists, craftspeople, and construction managers.