U long--which is never a
_simple_ Vowel-Sound--as in _union_, pronounced _yioonyun_.

This Diphthong IU (or yiu) denotes _Conjunction_, _Conjuncture_, _Event_
(the two ends meeting); and also _Coupling_ or _Unition_; a central
point between extremes.

The next and the most important of the Diphthongs (except AU) is AI,
compounded of the third (A) and the first (I) of the simple
Vowel-Sounds. It is pronounced very nearly like the English long I, as
in p_i_ne, f_i_ne, etc., which is not a _simple_ Vowel; but is
compounded of the two simple Vowels above mentioned (A and I, ahee) in a
very close union with each other; or, as it were, squeezed into each
other. The Tikiwa (Tee-kee-wah) combination (this is the name of the
Scientific Universal Language), AI, is not ordinarily quite so close,
and when pronounced _long_, is quite open, so that each Vowel is
distinctly heard (ah-ee).

This Diphthong AI may be regarded as embracing and epitomizing the lower
or ground wing or half of the Simple Vowel-Scale (I E _a_ A); its
meaning is, therefore, that of BASIC or SUBSTANTIAL REALITY: the GROUND
of Existence.

Contrasted with this is the next Diphthong, _O_I (aw-ee), compounded of
the fifth (_o_) and the first (I) Vowel-Sounds. It is the Sound of _oy_
in b_oy_. The I contained in this Diphthong may be regarded as standing
in the place of U at the other extremity of the Scale. This last Sound
has a tendency to return into I through the French slender U,
illustrating the Principle of the Contact of Extremes. The Diphthong
_O_I may, therefore, be viewed as embracing and epitomizing the upper or
ethereal wing or half of the Simple Vowel Scale (_o_ _u_ O U); its
meaning is, therefore, that of AERIAL or ASCENDING REALITY; LOFTINESS or
LOFT.

Next there occurs a Diphthong OI, pronounced as the same letters in the
English word g_oi_ng, which has a half claim to be ranked with the
Leading Diphthongs. It is sometimes reckoned into, and sometimes out of,
the Scale--like _a_ among the Simple Vowels. Its meaning is that of
FRONTNESS, PROSPECT.

Finally, the great Focal Diphthong, that which includes and epitomizes
the whole Vowel Scale, is AU (ah-oo), compounded of the third
Vowel-Sound (A) and the Seventh (or Eighth) U. It is the sound heard in
_ou_r, or in the Spanish c_au_sa. The meaning of this Supreme Diphthong
and general Vowel Representative is UNIVERSAL REALITY. It stands
practically in the place of all the Vowels, in the Composit