The QWERTY layout is a fine example of a fossil. It is

sometimes said that it was designed to slow down the typist,

but this is wrong; it was designed to allow *faster* typing -

under a constraint now long obsolete. In early typewriters,

fast typing using nearby type-bars jammed the mechanism. So

Sholes fiddled the layout to separate the letters of many

common digraphs (he did a far from perfect job, though; "th",

"tr", "ed", and "er", for example, each use two nearby keys).

Also, putting the letters of "typewriter" on one line allowed

it to be typed with particular speed and accuracy for demos.

The jamming problem was essentially solved soon afterward by a

suitable use of springs, but the keyboard layout lives on.