Sholes discovered that many English words contained combinations of letters next to each other in the alphabet. ... His solution was as simple as it was ingenious: move common letter-pairs away from each other. He went about the task in a scientific way. He got the educator Amos Densmore (his sponsor's brother) to prepare a frequency study of letter-pairs in the English language. He then used the study to split up as many common letter-combinations as he could and scatter them across his keyboard. When he was finished, the result was the alphabet soup that is the QWERTY keyboard. -- Torbjörn Lundmark: Quirky QWERTY, University of New South Wales Press, Sydney (2002).
Wrong. The most common letter-pair in English words is "th", which is placed adjacently in the QWERTY keyboard. The second is "er" + "re", also placed in the neighborhood of one another. They never stay away in the QWERTY keyboard. Mr. Lundmark's story does not tell the truth of QWERTY.
Additionally, Mr. Amos Densmore was not an educator at that time in 1860's. He was then a proprietor of Densmore Oil Company at Meadville, Pennsylvania, which manufactured train cars for transporting petroleum (cf. U. S. Patent No.53794).