Indicated High Primary Back Glide
Glides are only transitional sounds. They are intermediate to Consonants and Vowels, combining the characteristics of certain central-aperature consonants with the wide or expanded quality of vowels, but differing from vowels in not having a fixed configuration. ...in representing glides the peculiarities of consonants and vowels are blended: the accented fingers, by being straightened, contribute a consonant characteristic; while the second phalanx of the thumb, by being held at an angle to the plane of the palm, imparts to the glide positions the wide, without giving them the firm, quality of vowel positions.
Glides-Indicated positions are distinguished by having the accent finger straightened, and the accented voice phalanx of the thumb in contact with that finger's second phalanx. They are adapted to illustrate the easy transition from Vowel to Glide. Glides-Indicated possess exactly the same phonetic value and significance as the Glides which they respectively replace. When used with a High Vowel, have the third finger accented. Primary glides-indicated have closed unaccented fingers. Back Glide-Indicated positions, being posterior, have the palm held laterally at an angle to the arm.