By Mary Morrell | Correspondent

Soaring nearly 160 feet above the nave in the Basilica of the National Shrine of the Immaculate Conception, Washington, D.C., is the Trinity Dome, an artistic wonder which holds a unique status.

Msgr. Walter R. Rossi, rector of the Basilica since 2005, shared that during his years at the Shrine there have been interior enhancements, chapels added, mosaic installed on domes, a Rosary Walk and Garden dedicated, and even a canonization by Pope Francis. But once the mosaic ornamentation of the Trinity Dome is finished, a vision that had taken seed more than 100 years ago will be fully realized.

“The Trinity Dome completes the Shrine after 97 years,” Msgr. Rossi said, referring to the laying of the Basilica’s foundation stone in 1920.

For the past two and a half years, artisans, architects, laborers and engineers have been engaged in an intensive $20 million project to complete the artistry of the dome, according to the original architectural and iconographic plans of the National Shrine.

An excerpt from TrinityDome.org explains, “Every stone and artistic nuance of the Basilica proclaims our nation’s relationship with Mary, a spiritual bond formalized in 1847 when Pope Pius IX proclaimed Mary as ‘Patroness of the United States under her title of the Immaculate Conception.’”

By the time of the dedication of the Trinity Dome, scheduled for Dec. 8, some 14 million pieces of Venetian glass, called tesserae, in a thousand hues, will create a masterpiece depicting the Holy Trinity, Blessed Virgin Mary as the Immaculate Conception, a procession of angels and saints who have an association with the United States and the National Shrine, the Nicene Creed and the four evangelists.

Pope Francis blessed the preliminary Nicene Creed segment of mosaic during his visit to the Basilica Sept. 23, 2015. The segment contained the words of the beginning and end of the Creed: “I believe in one God.” “Amen.”

The mosaic will cover more than 18,300 square feet of the dome surface and will weigh 24 tons.

Behind the Scenes

One of five distinctive domes that grace the Great Upper Church of the Basilica, including the Incarnation Dome, the Redemption Dome, the Sanctification Dome, and the Glorification Dome, the Trinity Dome is the last to be completed, unifying all five into a coherent storyline ending with the Christ In Majesty mosaic on the north apse wall. Together they form a timeline of the New Testament.

Finishing the mosaic work for the Trinity Dome came with unique challenges, requiring great engineering and coordination to maintain daily operations for the National Shrine, which is open 365 days a year and welcomes some one million visitors annually.

Establishing a safe work site in the midst of the nave, which remained open throughout, necessitated the building of a deck, which served as the base of an enclosed compartment, six floors above. Eight floors of scaffolding rose above the deck in the enclosed compartment to the apex of the dome where the oculus, a circular opening at the center of the dome, marks 159 feet above the nave.

The elevated deck and enclosed compartment were anchored into the structure of the Basilica, rather than from the floor, allowing for the regular schedule of Masses, pilgrimages, tours and other events to take place below.

Martin Rambusch, of Rambusch Decorating Company, Jersey City, the company responsible for the artistic design elements of the project, explained that beginning with the first small-scale sketch of the dome’s artwork, each step of the project, including fabrication and installation, undergoes a series of reviews, adjustments and approvals. It is especially critical, he said, that “the faces of people who are definable, like Mother Teresa and Pope John Paul II, must be correct.”

Creating a Masterpiece

Rambusch also explained the process of the reverse method, invented in 19th century Italy, which was being used in the fabrication of the mosaic by Travisanutto Mosaics of Ravenna, Italy.

Fabricated in the studio, the mosaic is created in reverse with the tesserae individually affixed by artisans on sections of paper using a paste made from flour and water. Once all the sections of mosaic are completed in this way, they are delivered to the site for installation, “a giant puzzle in reverse,” said Rambusch.

Thirty thousand sections of the Trinity Dome mosaic “puzzle” were packed in 60 boxed crates and shipped by air and boat from Venice to the Basilica. Artisans from Rugo Stone, Lorton, Va., painstakingly installed the mosaic, cementing the sections to the very precisely mapped dome, paper side showing. After installation, the artisans gently dissolved the paper and flour paste using water and soft brushes and sponges to reveal the new mosaic.

The goal has been to complete this final project in preparation for the upcoming 2020 celebration of the 100th anniversary of the placing of the foundation stone. Thankfully, due to the generosity of American Catholics and the steadfast work of architects, engineers, artisans, installers and other laborers the Trinity Dome will be dedicated in December, said Msgr. Rossi.

Vision of Faith

The architect for this 100-year-old vision of the National Shrine was Bishop Thomas J. Shahan.

In 1910, one year after being appointed rector of The Catholic University of America, then-Father Shahan shared his vision for a university cathedral with a friend, writing, “I have always admired a great free open space, unbroken by columns, an ideal space for preaching and singing, for seeing and hearing.   Its wall spaces and ceilings ought to be covered with noble historical frescoes depicting the origin and the glories of Catholics in the United States, and particularly in these parts. … In a word, no one would think he had truly seen the Capital of the Nation unless he had paid a visit to this Church. … it would be a monument of artistic truth and sincerity, and thus a mirror of all the beauties of our venerable and holy religion.”

Three years later, Pope Pius X approved plans for the building of a national shrine in the United States, and made a personal contribution for its construction. That same year, the board of trustees of The Catholic University of America donated land at the southwest corner of the campus for Father Shahan’s vision for the shrine.

The National Shrine was dedicated Nov. 20, 1959, the same year that the superstructure of the Great Upper Church was completed. Embellishment and ornamentation of the interior has continued ever since.

Today the Basilica, affectionately referred to as America’s Catholic Church, is the largest Roman Catholic Church in North America and one of the 10 largest churches in the world. It was designated a National Sanctuary of Prayer and Pilgrimage by the U.S. Conference of Catholic Bishops.

The Basilica is now a separate entity and continues to serve the university community, along with pilgrims from across the nation and around the world.

When Pope John Paul II came to visit the Basilica in 1979 he acknowledged that the Shrine “speaks to us with the voice of all . . . the sons and daughters of America, who have come here from the various countries of the Old World. When they came, they brought with them in their hearts the same love for the Mother of God that was characteristic of their ancestors and of themselves in their native lands. These people, speaking different languages, coming from different backgrounds of history and traditions in their own countries, came together around the heart of a Mother they all had in common.”

In 1990, Pope John Paul II formally declared the National Shrine a minor basilica.

Devotion to Mary

In light of the completion of Trinity Dome, and the National Shrine, Msgr. Rossi reflected, “Since religious art is meant to move people to greater faith and devotion, my hope is that when pilgrims look up at the Trinity Dome and ‘seek those things that are above,’ they will see the Trinity, they will see Mary and the 13 saints, who all strove for a blessed life and who give example on our own path to holiness.”