In the mid-1800s, pioneer children sang as they walked and walked and walked, and thanks to a handmade wooden odometer attached to the wheel of one of their wagons, today we know they walked exactly 1,032 miles.
Combining early pioneer accounts with his knowledge of gear design, Brigham Young University mechanical engineering professor Larry Howell has built a working replica of the odometer used on the Mormon Trail. A study of the research he conducted to build the replica will be published in the proceedings of the American Society of Mechanical Engineers' "History of Mechanisms Symposium" to be held in Philadelphia in September.
"When I realized that although the pioneers were in tough circumstances out in the wilderness they took the time to do a research and development project to help other people, I wanted to do my own project to recognize their contribution," Howell said.
As an engineer Howell has always had an innate desire to solve problems and push the boundaries of technology. His research usually focuses on designing machines that are so tiny a person needs a microscope to see them, but several years ago a trip to the Museum of Church History and Art of The Church of Jesus Christ of Latter-day Saints piqued his interest in the much larger odometer and how it worked.
Although the pioneer odometer was not the first odometer ever built, Howell was impressed with how its design, implementation and accuracy paved the trail for western emigration.
As he investigated the odometer he found that it was designed and built by a team, much like an engineering project is accomplished today. Brigham Young sponsored and managed the project, Orson Pratt acted as the design engineer and Appleton Harmon was the craftsman. William Clayton, whose role ultimately decided the success or failure of the odometer, defined the needs of the project and kept records of the building process.
Howell's research into building his replica began by reading the descriptions of the odometer left behind in Clayton's 160 year-old journals. Unlike the devices in today's cars, the pioneer odometer did not automatically record the number of miles a wagon traveled each day. Clayton was assigned the tedious task of watching the odometer's count to produce a daily tally. Later during his journey, a device was made to count every 10 miles, but rain caused its wood to swell and break. Clayton returned to laboriously counting each mile for the rest of the journey.
Other odometer replicas exist, like the one Howell saw at the Museum of Church History and Art and another at the Mormon Trail Center at Winter Quarters, Nebraska. But before Howell's work, it was assumed that there was not enough information to determine the accurate dimensions of the odometer. Although the number of gear teeth was known, the precise dimensions of the gears were not. Howell combed through Clayton's records to gather enough information to create a long system of algorithms, explicit step-by-step mathematical procedures that allowed him to plug in what he knew about the odometer to solve for what he did not.
Under Howell's direction, graduate student Joey Jacobsen constructed the first replica of the odometer to the proposed dimensions. The odometer is 18 inches long, 15 inches high, 3 inches thick and is made up of four gears turning on three shafts. Surrounding the original wooden odometer was a casing that protected it from harsh weather.
"Some people think that such a simple machine is insignificant, but it had a major impact on society. It is important that we are recognizing that," Jacobsen said.
Clayton published the information he gathered from the original odometer in his "Latter-day Saints' emigrants' guide" in 1848. The guide provided detailed maps and descriptions for travelers going through Salt Lake City and on to California. This brought unanticipated opportunities for money and trade to the Latter-day Saint community, which struggled in its infancy.
The scholarly paper Howell has written about his research into the odometer also discusses first-person accounts from the trail, reviews lingering misconceptions about the odometer, reports its actual gear sizes and stresses its impact on Western settlement.
"It's hard to imagine what it would have been like to make this device in the wilderness and to be the first to measure these distances across the country," Howell said. "Studying the pioneers and their altruistic work provides valuable insights for us today and helps us remember our heritage."