QWERTY was devised by Christopher Sholes, who began his typewriter-building experiments in 1867. Sholes's first keyboard used piano keys in a single row, with the letters in alphabetical order. But he was soon forced to change that arrangement, because his type bars responded sluggishly. When he struck one key soon after another, the second key's type bar jammed the first bar before the first could fall back, and the first letter was printed again. Key jamming was still an occasional problem some 80 years later, when I had chicken pox, but at least by then the type bars struck the paper from the front side, so you could immediately see what was happening and separate the keys with your fingers. Alas, with Sholes's machine and most other typewriters until the early part of the century, the type bars struck the invisible rear side of the paper, and you didn't know the bars had jammed until you pulled out the page and saw that you had typed 26 lines of uninterrupted E's instead of the Gettysburg Address. -- Jared Diamond: "The Curse of QWERTY", Discover, Vol.18, No.4 (April 1997), pp.34-42.
Mr. Christopher Latham Sholes' first type-writing machine, whose patent was filed on October 11, 1867, had a two-row keyboard, neither single-row nor piano-like (shown right, taken from U. S. Patent No.79868). Mr. Sholes adopted a piano-like keyboard in his second model that was patented on June 23, 1868 (cf. U. S. Patent No.79265). His second model had a two-row keyboard with twenty-eight keys (A to Z, comma and period), which resembled the Hughes-Phelps printing telegraph, as I mentioned before. Prof. Jared Diamond didn't investigate the early type-writing machines by Mr. Sholes, but did write an imaginative story about them.