Santa Fe's self-promotion of its heritage sometimes defies arithmetic.

In 1883, the city planned a "Tertio-Millennial" — a term contrived to mean one-third of 1,000 or 333.

The problem was, that didn't add up.

Santa Fe, then thought to have been founded in 1610, would not reach its 333rd year until 1943 — 60 years later.

But that didn't discourage the party planners.

The New Mexican, which became one of the exposition's most ardent promoters, started off its coverage with an erroneous headline — "One Third of a Century" — indicating how puzzling the term Tertio-Millennial may have been to people of the late 19th century.

But when newspapers in Denver and elsewhere questioned the timing of the anniversary, The New Mexican began to defend it, contending that the celebration commemorated "not the founding of the city but (New Mexico's) occupation by the Spanish people and its coming under the influences of European civilization and the christian religion."

An editorial argued that the first Spaniard to explore New Mexico was Alvar Nuñez Cabeza de Vaca in 1538-39, that Francisco Vásquez de Coronado led an armed incursion in 1540-42 and Juan de Oñate established the first colony in 1598. None of those years coincided with a 333rd anniversary, either, and no event was cited from 1550 — exactly 333 years before 1883. But the editorial concluded: "In light of these historical facts it will be seen that the Tertio-Millennial is an appropriate name for the celebration which is about to commence under such favorable auspices."

Centennials were the rage in the Victorian Age. The United States had celebrated its first 100 years only seven years earlier. The Tertio-Millennial was Santa Fe's first attempt to promote itself since the transcontinental railroad line reached Lamy in 1879, and the spur was extended to Santa Fe the following year.

Mining companies set up booths with examples of their ores, sites and techniques in the exhibition hall erected two blocks north of the Plaza, using the walls of the unfinished "state house," finished later as the U.S. Courthouse. An oval horse-racing track was constructed around the exposition grounds.

Celebrations began July 2, 1883, with a turnout of 10,000 to 12,000 people. "The formal inauguration of a month's festivities was carried out amid much splendor and unbounded enthusiasm," reported The New Mexican. "The morning dawned bright and beautiful. At 9 o'clock, the first of a salute of thirty-three guns, fired at minute intervals, signaled the crowd into the streets." The evening concluded with "excellent music, graceful dancing and a genuine good time," despite an evening downpour.

The Tertio-Millennial continued for a month, with races of all types, American Indian dances and pageants, including on three successive days, re-enactments of three centuries of history in New Mexico. On July 17, someone tried to burn down the exhibition hall. By early August, as the exposition neared an end, some appeared to grow tired of the controversy surrounding the Tertio-Millennial.

"We now respectfully ask the zealous and hearty support of the whole press of the territory for the exposition," state mining commissioners said in a proclamation. "Now we ask the united press of the territory to sink out of sight for the time being all personal or local feeling with reference to anything unpleasant connected with the exposition heretofore, and join with us unanimously in pushing the high and patriotic objects of the exposition from now until the close."

Contact Tom Sharpe at 986-3080 or tsharpe@sfnewmexican.com.