had an organ mechanism. The largest of the three instruments constructed by Steinmeyer on Psachos
designs was also an organ. The other two were harmoniums, one of which is kept today in
in Athens.
In the
“Ioakimion Psalterion
” the octave was equally divided in 36 minimum intervals, limited by the all white keys of the keyboard. Over the keys was adapted a sliding ruler
(
“Canon
”) with buttons, the disposition of which represented the diatonic scale (consisting of two equal disjunct tetrachords). By sliding the
“canon
” over the keyboard and playing on the buttons, the scale was transposed to whatever pitch wished. On the
“Evion Panharmonion
” the 42 pitches within the octave correspond to 42 keys placed within the span of a piano octave. The
succeeding intervals are different to each other and there are not even equally divided tetrachords in one octave. Comparing the intervals produced by the two instruments, it is observed that the
“psalterion
” has considerable similarities to equal temperament – the influence of which it was wished to resist – though
Psachos
’ instrument is related, for the most, to pure intonation.