RE: Difficulties in Piano Construction

>Several books I have read say that one of the largest reasons for the
>popularity of Equal Temperament in western music is that the most
>prominent piano manufacturers all decided to make pianos in ET, and that
>constructing a JI piano creates some serious mechanical difficulties.
>However, the books have never mentioned what these mechanical difficulties
>are. Does anyone have any input on this question? It is one of the last
>unanswered questions in my music perception thesis in which I compare
>perception of ET with perception of JI in certain circumstances. I need
>to finish by fri.

No doubt these mechanical difficulties have to do with all the
additional notes that would be needed. The simplest scheme that produces
near-enough (all errors less than 1/4 cent) JI in 12 keys is Helmholtz'
schismatic temperament with 24 notes per octave.