ao H. W. Poole on Perfect Harmony, etc. 
cates in the usual manner with the valves or hammers. It will 
be understood that the mechanical construction of the instru: 
ment beyond the key-board may be the same as usual, oxcca 
that its we of pipes or mee must be multiplied. 
23. the assemblage of all the notes may confuse the eye 
at first sights I have drawn on half scale the plan of the finger- 
keys which in every signature—or commencing on any white key 
whatever—give the a and double diatonic scales. The white — 
keys are of the width of 0-998 in., the black keys aiid the | 
width of 0°45.* The white keys on the common key-board are 
but 0°93, or the seventh of 64 inches. The plan in fig. 2 will en-— 
able a player to judge whether the scale can be executed. Itis 
immediately intelligible even to a child, who, ag a | 
the order in one key, knows it in every other. The keys are _ 
—— by their relations to each other, that is, as Dy, Re, 
and (to repeat it again), Do may be taken on any white key. — 
The fingering in the triple diatonic scale is the same as in that 
of the natural key, and of others, on the common key-board, © 
and the fingers easily reach the keys and change on Fa and Do © 
as in the latter case. In the following scales the usual signs © 
represent the thumb and four fingers; see fig. 
TRIPLE D1atonic ScaLE—Jis ‘adbiig: 
Do Rez mi Fa at la si Do 
ES 1 2 4: 2 3 4 (or +) 
DovusiEe Diatonic oe eee: 
Fa So. la Se Do mi Fa 
— 1 2 3 + * 3 3 
The player is recommended to complete the octave, Fa to Fa, — 
by copying the four lower keys, Do, Re, mi, Fa, figs. 2, 3, and 
ese he lower Do upon the upper one, or ‘by conceiving that — 
» done this pe y & 
is will show the double scale in its reg- 
grams by the data given, and I shall, therefore, give the finger- 
ing for _— chords, which being un nderstood a one key will 
be the same in all transpositions. 
* The widths are established thus: first determine the width of the octave, and 
that of the black keys. pee nr amb and b, the width of 
the white key (W), is obtained thus: —'°-—w. For the key-board for major 
Bega ay Sm Be See & eee em 
