If Central Congregational had earlier created an exceptional edifice on Benefit Street in calling on Thomas Tefft in 1850 to design one of the first examples of monumental American Romanesque Revival ( PR83.6), this replacement is equally so—and not only as a surprising bit of Spanish baroque for New England Congregationalism. Carrère and Hastings came to Providence at the request of Francis W. Carpenter soon after the architects completed commissions in St. Augustine, Florida, that drew on local historical traditions, including the Ponce de León Hotel (1885–1887) and, more to the point, Memorial Presbyterian Church (1889–1890), where their patron, the famous railroad tycoon and real estate developer Charles Flagler, had a domical memorial chapel for his family built as a semidetached structure. It may have been momentum from the immediately previous work, or simply Carpenter's enthusiasm for what he had seen during a Florida sojourn, that accounts for this unusual conjunction of New England Congregationalism with a southern European and Counter-Reformation style, albeit here treated in a restrained manner. The Spanish Floridian origins of the church were more evident before neglect and a 1954 hurricane eliminated the elaborately ornamented, cupola-ed mini-towers, mostly in terra-cotta, from the corners of the elevations, where painfully rudimentary replacements now exist. Yet, even missing these culminating ornaments, the front is exquisitely wrought and proportioned in the tawny combination of narrow Roman brick and terra-cotta trim which McKim, Mead and White had popularized.
Of primary interest, however, is the interior, which unites concurrent trends in American architecture of the time: Renaissance monumentality and the earthy and naturalistic aspects of the Arts and Crafts Movement. In this cross-shaped space, the broad, stubby arms for the nave and their more extended (perhaps too extended) transepts are barrel-vaulted in Guastavino tiles which swell upward into the central dome at the crossing, and outward into the broad, semicircular apse. This indigenous Catalan technique of vaulting by means of thin, overlapped tiles set in concrete, which Rafael Guastavino brought to the United States from his native Barcelona, had three structural advantages. Because the vaults were built up of progressively projecting layers of tile embedded in concrete, they required minimal scaffolding and centering to erect. Because the materials did not have to be custom shaped and fitted, like cut stones, fabrication was cheaper and quicker. Finally, because the finished vaults were much lighter than those built of cut stone, they could be more economically supported. (The company Guastavino organized played a cardinal role in spanning the grand public spaces which the American Renaissance called forth from the 1890s through roughly the 1930s—and indeed made most of them economically possible.)
The apse is painted with illusionistic panels decked with jewellike patterning and entwined grape leaves in muted mauves, pale greens, and ivory, set against the clay tan of the tiles, all of which were colors popular in Arts and Crafts interiors of the time. Stained glass windows designed by J. A. Holzer (an artist-craftsman who had previously been one of Tiffany's top designers) and fabricated by the Duffner Kimberly Company fill either end of the arched transepts. In their proscenium scale, theatrical brilliance, and technical virtuosity, these are unsurpassed in the state. The theme is divine life unfolding in the universe: the Creation toward the east and the vision of the heavenly city of the New Jerusalem toward the west, with lesser windows
The architects were probably responsible for the design of the handsome pulpit lifted to one side of the apse and reached by a semicircular stair, along with most of the other furniture. They may also have designed the carefully shaped illuminated cross suspended in the space from the center of the dome, boxed in metal, faced with translucent glass, and outlined with tiny exposed bulbs, as a testament to the wonder of the time at the emerging technology of electricity.
The building committee specifically wanted a unified, “artistic” interior which would not depend on generations of gifts for its completion. It all comes together with a certain bluntness and spareness which is Congregational, as though this spare faith drew the threatened opulence of the building back in the nick of time from anything too Episcopalian or Catholic. Among all church interiors in Providence this probably stands next in architectural interest after the colonial and early national interiors of the First Baptist and First Unitarian churches, and is more unusual than either of its predecessors.