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Ad Quadratum Construction and Study of the Regular Polyhedra

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MN<br />

ML<br />

141<br />

1<br />

3<br />

LN 2<br />

<strong>and</strong> <br />

LM 3<br />

And <strong>the</strong> following ratios can <strong>the</strong>refore be read <strong>of</strong>f <strong>the</strong> graph.<br />

JH<br />

LH<br />

3<br />

1<br />

HA 2<br />

<br />

HG 1<br />

LM<br />

LN<br />

EK<br />

EF<br />

3<br />

2<br />

4<br />

3<br />

A tripling <strong>of</strong> frequency => a twelfth (g’) (sol’)<br />

= octave + fifth<br />

The octave ratio (c’) (do’)<br />

(ascending fifth) (g) (sol)<br />

(ascending fourth) (f) (la)<br />

LN<br />

FK <br />

2<br />

3<br />

<br />

1<br />

4<br />

2 4 8<br />

<br />

3 1 3<br />

EK<br />

FK<br />

(7+5) in terms <strong>of</strong> position<br />

2 3 <br />

3<br />

in terms <strong>of</strong> frequencies.<br />

2 <br />

(octave + fourth) (f’) (fa’)<br />

4<br />

4 (double octave) (c’’) (do’’)<br />

1<br />

All elements to build <strong>the</strong> Pythagorean scale are <strong>the</strong>refore at h<strong>and</strong>. The graphical scale<br />

shown on fig. 83 indicates <strong>the</strong> ratios just obtained. Those missing, shown in brackets, are<br />

easily obtained since <strong>the</strong> value <strong>of</strong> <strong>the</strong> tone 9 <br />

<br />

8<br />

<br />

is known thus:<br />

<br />

e 9 9 81 3 9 27 27 9 243<br />

; a ; b <br />

8 8 64 2 8 16 16 8 128

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