Writing in The New York Times this month, the science correspondent John Noble Wilford described the wonders that the Inca executed with simple fiber, including grasses and alpaca and llama wool.
He wrote: “Conquistadors from Spain came, they saw and they were astonished. They had never seen anything in Europe like the bridges of Peru. Chroniclers wrote that the Spanish soldiers stood in awe and fear before the spans of braided fiber cables suspended across deep gorges in the Andes, narrow walkways sagging and swaying and looking so frail.”
A course in “materials in human experience” at the Massachusetts Institute of Technology provided the news hook for the article. Working on flat, dry land, students there built a 60-foot-long fiber bridge along the lines of those the Inca made to cross unforgiving rivers. They wove 12 strands of twine (from a fiber called sisal) to create rope, and braided 12 lengths of rope to form cables, these to stretch across two campus buildings.
It’s hard to imagine turning wispy fiber into cables as the Inca did (“some as thick as a man’s torso,” Wilford wrote). For a visual tutorial in the mechanics, you might watch a 60-minute NOVA documentary called “Secrets of Lost Empires: Inca.” The documentary shows the making of a bridge in three days, beginning with harvesting blades of grass. Far down below runs a fast-moving river, and you can understand one NOVA researcher’s reluctance to walk across the bridge, full of openings and swaying in the wind. (The list price for the video is $19.95, but used copies are available on Amazon for about $11).
The documentary also shows a team of experts trying to replicate the near-perfect fit of Inca stone walls (able to withstand earthquakes and centuries of time), with handheld stones shaping massive blocks. We see these modern masons patiently chipping away to create a tight seam of interlocking block — no mortar allowed. But how to get the stone block to the wall in the first place? In one memorable scene, 250 men, women and children use thick ropes to demonstrate that it is possible to move a 15-ton monster block across the ground, as the Inca might have done in traveling from a quarry to a building site. (Call for backup: some Inca blocks weighed up to 100 tons.)
Anyone within reach of Chicago would do well to see a new exhibition at the Field Museum, “The Ancient Americas.” The Inca and the Aztec are featured cultures; both used military conquest and political alliances to become superpowers of their day, overseeing vast empires. In 1525, when the Anabaptists were reshaping the religious landscape in Europe, the Inca lorded over a 3,000-mile coastal empire, from Ecuador to Chile.
The Inca called their empire “the Land of the Four Quarters,” reflecting their four political regions. The capital was Cuzco, centrally located, if 11,000 feet high in the Andes, and known as “the navel” in the Quechua language. The Times article mentioned that the last existing Inca suspension bridge is near Cuzco, at Huinchiri; each year the bridge is refurbished during a three-day festival (the NOVA team got its footage here) . With luck, we might time a field trip to Machu Picchu to take in the bridge work.