WYSO Curious is our series where listeners ask questions and WYSO producers find the answers. Today’s question comes from Jeff Wilson in Vandalia. Jeff had seen a photo in the Wright Brothers Museum of a curious geological formation called the Pinnacles, and he wanted to know more about this Dayton Landmark.
In the 1800s, there was an unusual geological formation along the Miami River just south of Dayton. Known as the Pinnacles, or Devils Backbone, the towering formations were a popular recreation spot for locals.
"The pinnacles themselves seems to be an area where there’s been erosion and ridges and sort of pyramidal structures," says Dr. Michael Sandy, a geology professor at the University of Dayton. He first learned about the Pinnacles through a book by August Foerste. "[He was} a preeminent geologist in the Dayton area, and in 1915 he published a book describing the geology of Dayton, and there is a photograph of the Pinnacles."
The black and white photo shows a tall column of earth towering above a small silhouette of a man dressed in 19th Century clothes.
"On the northern meander the river is going up and eroding a river cliff into the glacial sediments that were deposited here a little bit under twenty thousand years ago. The sediment it’s not hard rock, is geologically young, it’s soft, and you can get all sorts of interesting erosional landforms and features, and that’s really what the Pinnacles is. The Devil’s Backbone is this sort of ridge that is above the river, kind of extending through the pinnacles and a little bit further to the east as well."
These formations were located in Moraine, which is named for this geological area.
"A moraine is a glacial deposit. As ice melts it can leave significant deposits of sand, gravel, clay," says Sandy. In the 1850’s a railroad went in along the base of this area, "And I think that was really the death knell of the pinnacles. I was out there this morning looking at it. It’s tree covered, it’s vegetated, the slope’s lost it’s very steep angle and it’s just covered over with vegetation."
Although the Pinnacles no longer exist physically, their role in aviation keeps this local landmark alive.
Nancy Horlacher is the local history librarian for Dayton Metro Library. She is a charter member of the Wright Brothers research committee, and a former curator at the Carillon Historical Park
"And the Wright Brothers exhibit was part of what I curated there," she says.
So remember Dr. Foerste who was mentioned earlier?
"Dr. Foerste wrote the book Geology of the Vicinity of Dayton, which was a highly acclaimed book," says Horlacher. "He was also a national, and international noted geologist and paleontologist, and he taught for 38 years at Steele High School. Before Steele there was Central High School, and Orville took classes in science and was taught by Dr. Foerste. That may be one reason they went to the Pinnacles, to observe the birds that were flying there."
In the summer of 1899 the Wrights developed their wing warping theory while watching the birds at Pinnacle Hill, which in turn gave birth to modern aviation.
"The brother’s needed to solve one piece of the puzzle for flight. They had already solved pitch and yaw. Pitch is the way the airplane would go up and down. Yaw would be turning right to left. But, it took them observing for two years, the birds, especially the buzzards in the Pinnacles that were flying in the drafts."
The buzzards wing tips would go down and up, seperate from the wing being all one piece, which is how they bank and turn, and according to Horlacher, "That was the crucial piece to flight."
So even though the pinnacles are no longer around, they live on in history, every time you see a plane flying in the sky.
Editor's note: the audio version of this story refers to the archival photo as featuring a silhouette of a man in 18th century clothing. The text correctly refers to silhouette of a man dressed in 19th Century clothes.