Once upon a time, Iowa was the center of the universe.
In August 1869, exactly 150 years ago, scientists and sky watchers descended on Iowa to study a solar eclipse. It was the Midwest’s last total solar eclipses of the 19th century – and the first to be photographed.
“This eclipse was the first time in history that wet-plate photography was used in connection with astronomy,” said historian Jerry Rigdon, a former mayor of Burlington. “Total eclipses occur on average every 18 months but are only visible on less than half a percent of the earth’s surface. So the total solar eclipse observed at Burlington and much of Iowa was a very rare occurrence.”
Indeed, a total solar eclipse darkens any given point on earth only once every 350 to 400 years because the sun, the moon and the earth “have to align exactly,” said Charles Kerton, professor of astronomy at Iowa State University. “They don’t have to be off by much for the shadow to miss the earth entirely.”
In 1869, scientists from as far as Montreal and London traveled to Iowa to set up their telescopes and new-fangled cameras along the eclipse’s anticipated path, from Sioux City to Cherokee, Jefferson, Des Moines, Mitchellville, Oskaloosa, Ottumwa, Mount Pleasant and Burlington. Others camped out in Cedar Falls and Davenport to document their findings from a different angle.
On the big day, the eclipse emerged shortly after sunrise over the Pacific Ocean east of Japan. The 155-mile-wide shadow swept northward in a graceful arc to Alaska before swooping southeast through Canada, the continental United States and the mid-Atlantic Ocean.
The anticipation in southeast Iowa was almost palpable, according to The Burlington Hawk Eye.
“Men walked more softly and spoke in lower tones of voice. And for some minutes before the appearance of the moon, the hum of conversation had died away, the members of the party were all at their respective spots, and expectation was on tiptoe,” the newspaper reported on Aug. 11, 1869.
The eclipse started in southeast Iowa just before 4 p.m., while astronomers hovered over their equipment and white-clad “religious fanatics” waited for the world to end, according to a 1970 account in The Palimpsest, a former publication of the State Historical Society of Iowa.
Spectators in Davenport noticed an instant change in the atmosphere. Temperatures dropped five degrees. Swallows and doves flew back and forth because of the unexpected darkness. Groves of trees took on strange colors, changing from dark green to vapory yellow and then to a deeper shade of green.
By 4:20 p.m., the moon blocked half the sun. By 5 p.m., Venus and Mercury appeared in the darkened sky, and a few minutes later, the sun’s corona could be seen for 63 seconds. The total blackout lasted just under 3 minutes. The whole show finished by 6 p.m.
Afterward, the stars disappeared as sunlight returned. Birdsong welcomed the “second dawn,” and trees resumed their natural hue.
In all, the eclipse yielded about 160 photographs, from which scientists concluded that the corona is a permanent part of the sun. Their photos also revealed something called “Baily’s Beads,” an eclipse effect that occurs when sunlight shines through the valleys of the moon.
As the excitement surrounding the eclipse settled down, scientists packed up their gear and returned home to file their reports. In one write-up, professor Charles F. Himes of Pennsylvania’s Dickinson College wrote that, “favored as we were with a sky free from cloud or haze, and a beautiful point of view, this phenomenon left an inerasable impression upon our minds and hearts.”
But the most poetic account may have belonged to a professor named D. G. Eaton, in his report to the U.S. Navy: “I have climbed the Alps and visited London, Paris, and Rome, but would sooner lose the memory of them all than of those three minutes on Burlington heights.”
This article was provided by the Iowa Culture Wire, a free service of the Iowa Department of Cultural Affairs.