Now point to D, and say, What is that'?
and the answer will be, D.Ask, Is it a vowel or consonant, and they will reply, A consonant; but ask, Why do you know it is D, and the answer will probably be, It is so because it is.

Hide the circular part of the letter, and ask, What is the position of the other part, and they will say, having previously learnt the elements of form which will shortly be explained, A perpendicular line; hide that, and ask them what the other part is, telling them to bend one of their fore-fingers in the same form, and they will say, A curved line.

If they are then asked how they may know it is D, they will say, Because it is made of a perpendicular line and has a curved line behind.

Further information may then be given.

Turn the D letter up thus [Illustration: The character D turned on its side], and say, I want to teach you the difference between concave and convex: the under part of the curve is concave and the upper part of it is convex.