In words wherein visible vowels are necessary, and where the juncture of a visible vowel with the required consonant or consonants would be difficult or impossible to accomplish, a sign representing another sound of the same Roman vowel is substituted. For instance, it would be impossible to recognize the straight sign for long I, when joined to the letter P, and yet to properly read the word Pine, when it is a person's name, it is necessary to visibly represent the vowel sound. To do this we join the sign for short-i, and, in order to show that we intend the sound meant to be long-I, we thicken short-i, as it is shown in sign 26 in Exercise, which thickening tells us that it is substituted for long-I. Similarly, as shown in other signs in this book, other light vowels may be substituted to represent the long ones by thickening, excepting the sign for short-a, which is not needed to be substituted for long, ordinary A, because the sound for Ai can be better employed, as in sign 24 in Exercise, though as A and Ai represent sounds so very similar that most people make no difference in their pronunciation, it is not necessary to thicken either A or Ai when substituted for each other, either sign being used for the other without particular indication. In instances where the long sounds of O and Oo need to be shown, but will not join, the signs for their short sounds are used, and bowed in the opposite direction to show substitution, short-o being turned around in the form of a heavy letter Way, and short-oo, like a heavy short-u, as in signs 27 and 28 in Exercise. Short-oo, when made in the shape of a short-u, will not be mistaken for that letter; because, when the sign for long-U is substituted for the short one it is only shaded at one end of the curve, while short-oo is thick all over. The latter is shown in sign 28 in Exercise. For a similar reason short-u, when shaded to indicate the sound of long-U, will not be mistaken for the substituted short-oo.

When Oi is required to be added to B and similar shaped characters, it may be bowed in the shape of short-a, as in sign 31 in Exercise, and being written heavy will not be mistaken for short-a, as short-a is never thickened when substituted for any other sound of A.

To accommodate the downward stroke of Ow, the letter Hay is written upward, as in sign 25 in Exercise, but as Hay should generally be written downward, Ow would have to be written upward upon such other occasions.

Ah may be used for Aw by thickening beginning stroke. Sign 29.

Ah and short-ah may be substituted for each other without thickening.

The sign for Ah or short-ah may be substituted for A or short-a in instances where the regular sign for A or short-a would not join, as in illustrations further on.

This substitution of the vowel signs for one another, as shown in signs 24 to 31 in our Exercise, as above described, illustrate instances which will, however, very seldom occur, and need not cause any fear of confliction on the part of the student. The vowel signs will, in general, join easily when required, as they do in last lesson, without substitutes.

If students prefer, they need not join the vowels. Signs 31 and 32.