looking back

In 1923, Swarthmore professors and students traveled by train to the small town of Yerbaníz in the Mexican state of Durango. With help from Mexican politicians, astronomers, and workers, they built a temporary observatory to document the Sept. 10 total solar eclipse.

Did cloudy skies obscure your view of the April 8 total solar eclipse? Imagine if you had traveled from Pennsylvania to Mexico by train to observe it, only to have the sky open up and pour on the big day. That’s what happened to a group of Swarthmore professors and students in 1923.

Their mission was threefold: to capture large-scale photographs of the corona, to test Einstein’s theory that rays of light passing near a massive body in space would be visibly bent as they followed the curve created by the body’s mass, and to learn about the chemical composition of the corona and its motion.

For these purposes, they brought along one 65-foot camera, three 15-foot cameras, and three spectrographs. Joaquín Gallo, director of the National Observatory of Mexico, lent them books and other, smaller tools.

Arriving in the small town of Yerbaníz, in the north-central state of Durango, they found the train station partially destroyed as a result of battles in the recent Mexican Revolution.

“The entire seven weeks we lived in tents we had taken with us … undisturbed by telephone and other modern luxuries; even the radio worked poorly. Three days elapsed after the death of President [Warren G.] Harding before we knew of it,” wrote Professor of Mathematics and Astronomy John A. Miller, who led the Swarthmore expedition.

Miller and his team received the aid of Mexicans from every level of society: Jesús Agustín Castro, governor of Durango; the owners of Hacienda Catalina, where the team camped and built their temporary observatory; and many Mexican soldiers and workers, including cooks Luis and José.

Yerbaníz, “is in an arid region, and for four years prior to the eclipse almost no rain had fallen there,” wrote Miller.

But Sept. 10 was exceptional. “It rained in torrents for an hour; at 10 o’clock there was a stream of water half an inch deep flowing over every square inch of the camp,” he recounted. “The instruments were drenched and so were our spirits.”

Photos from the observation site tell a different story: A brass band performed on the day of the eclipse while vendors sold cerveza to thirsty moon-gazers. Perhaps the tone shifted at noon, when the weather finally began to cooperate.

“The clouds broke away,” Miller wrote. “At the beginning of totality and again at the end, there were light clouds floating over the region of the sun, but at mid-totality it was practically clear and continued so the remainder of the afternoon.”

—NIA KING