Sholes' machine had a rather sluggish action, too, because the type bars depended on gravity to fall back into place. They clashed and jammed. His first keyboard was laid out alphabetically, but then he moved the letters around to find a pattern which would make the type bars collide least. Finally, he wound up with the letters most frequently joined in words moved as far apart as possible. This is the standard keyboard today. -- Peter T. White: "Pyfgcrl vs. Qwertyuiop", The New York Times, Vol.CV, No.35792 (January 22, 1956), Magazine Section, pp.18,20.
As far apart as possible? No. In English the most frequently-used letter sequence is "th". On QWERTY keyboard, you see T and H are adjacently placed. The second is "er" + "re", also placed in neighborhood of one another. Mr. White was too credulous of enthusiasts for Dvorak keyboard.