Thomas Corwin Mendenhall (October 4, 1841 – March 23, 1924) was an American autodidact physicist and meteorologist. He was the first professor hired at Ohio State University in 1873 and the superintendent of the U.S. Coast and Geodetic Survey (now known as NOAA) from 1889 to 1894. Alongside his work, he was also an advocate for the adoption of the metric system by the United States and is the father of author profiling. Biography Mendenhall was born in Hanoverton, Ohio, to Stephen Mendenhall, a farmer and carriage-maker, and Mary Thomas. In 1852 the family moved to Marlboro, a Quaker community outside of Akron, Ohio. His parents were strong abolitionists and frequently opened their home to escaped slaves heading north along the Underground Railroad. Mendenhall became principal of the local primary school in 1858. He formalized his teaching qualifications at National Normal University in 1861 with an Instructor Normalis degree. While living in Columbus, Ohio, he married Susan Allan Marple in 1870. The couple had one child, Charles Elwood Mendenhall (1872–1935), teacher and chairman of the Physics Department at University of Wisconsin–Madison for 34 years. He taught at a number of schools in Ohio including Central High School in Columbus, gaining an impressive reputation as a teacher and educator. In 1873, although he lacked conventional academic credentials, he was appointed professor of physics and mechanics at the Ohio Agricultural and Mechanical College. The college ultimately became Ohio State University, Mendenhall being the first member of the original faculty. He was later awarded the first ever honorary Ph.D. from The Ohio State University in 1878. In 1878, on the recommendation of Edward S. Morse, he was recruited to help the modernization of Meiji Era Japan as one of the o-yatoi gaikokujin (hired foreigners), serving as visiting professor of physics at Tokyo Imperial University. In connection with this appointment, he founded a meteorological observatory to make systematic observations during his residence in Japan. From measurements using a Kater's pendulum of the force of gravity at sea level and at the summit of Mount Fuji, Mendenhall deduced a value for the mass of the Earth that agreed closely with estimates that Francis Baily had made in England by another method. He also made a series of elaborate measurements of the wavelengths of the solar spectrum by means of a large spectrometer. He also became interested in earthquakes while in Japan, and was one of